Most Significant Plumbing Interview Questions Part – 2

Q – 1 What is Garbage Disposal Smells?

Ans- Put ice cubes in the disposal (about 1/2 way), run the disposal, flush out with cold water. Next put 1/2 a lemon and grind it up.

Q – 2 Shower Stall on Concrete Floor Smells?

Ans- If you can see water in the trap , then the trap is holding water and you know it’s working. Even if the trap is undersized (1 1/2″; instead of 2″;) it would work. So the problem is probably a leaking drain pipe, the shower drain itself (the part that is connected to the shower stall) or it’s leaking where the two connect. Can’t fix the pipe or the drain itself without pulling the shower out.

But, if you can see a rubber or lead ring around the pipe as it sticks up into the shower drain – that can be removed and a new one put in. This is a pretty common practice in concrete shower installs.

Q – 3 What is Anti Hammer Device?

Ans- Up until 10/15 years ago we put in anti hammer tubes. The *powers that be* found that the tubes got water logged over time. So – it’s no longer code. In commercial installs, spring loaded devices are used especially at the end of long runs or at the end of a series of fixtures like urinals.

To replace the air in the anti hammers, drain down the water in the whole house with the faucets turned on. The idea is that when you turn the water back on it will compress the air at the highest point at the end of each pipe. That’s what the *powers that be* realized that plumbers were not plumbing for – and home owners would not do.

Q – 4 Rust in Dishwasher?

Ans- There is no way to clean rust out of old galvanized pipes. Most DWM s have a screen where the water connects to the machine. You access it through the lower front panel. Another solution would be to put a filter on just the hot water pipe to the DWM. If you replace the pipe – use copper – and connect to the old galvanized with a dialectic union.

Q – 5 Explain Burying water pipes outside?

Ans- Find out what the freeze depth is in your area and bury the pipes below that level. Here (Seattle area) it is about 2 feet. Use schedule 40 PVC for cold water and CVPC for hot (if you are running that out also).

Q – 6 What Type Pipe from Water Meter to House?

Ans- If the run from the house to the street is short (under 60 feet) I’d use *Type L * soft copper. It is less likely to break and it has no fittings in the ground except at each end of the pipe. I’d also put pipe (foam) insulation) around the copper run. For longer runs my next choice would be schedule 40 PVC pipe. Not a bad choice at all. I would not use flexible plastic – that is black *poly* pipe. It comes in a roll.

Way to soft and the metal clamps and hard plastic (or metal) connectors will break over time. I repair them weekly.
My Black Poly Pipe Pet Peeve My experience with black poly pipe (comes in a roll) is that it leaks. It is too soft. Hard surfaces (rocks) rub holes in it and where ever there is a transition to another type of pipe or an elbow it will leak there – because of the hard adapter, radiator clamps and the soft pipe. Schedule 40 PVC or copper is the best way to go with water mains.

Q – 7 What is Sizing Water Pipes?

Ans- If you lived alone, only using one plumbing fixture at a time – correct pipe size wouldn’t be a big issue. However when you are in the shower and someone flushes the toilet – it is a big deal. The basic rule is *two fixtures on a 1/2″; pipe*. You need min. 3/4″; incoming cold pipe for a one bath house. Just running 3/4″; to each fixture in the house won’t hurt, but there will be no real gain.

To size a water distribution system, get a copy of your state code book. It will spell it out in terms of beginning pressure, the furthest fixture from the meter and the number of fixtures in the house. Each fixture is worth *so many units* and you are allowed *so many units* for each size pipe as you get further from the meter.

Q – 8 Explain Copper Water Pipe Vs Plastic?

Ans- IMHO copper rules in most situations (unless you have low pH or aggressive water) ! Over time, the plastic can sometimes *sag* and possibly get brittle. If it needs to be repaired or altered in any way, the pipe will have to be glued and you will have no water ’til it dries.

Copper-you can solder, turn it on, test it and know that all is well. Any plastic to metal connection is weak, such as where the HWT connection is made. Mice and rats love many plastics. They chew on it to keep their teeth from growing through their lower jaw.

Q – 9 Garbage Disposals/Dishwashers and Septic Systems?

Ans- It’s my understanding that having a disposal is like having another person adding to the load on the septic system. So… are you currently under utilizing your system, over using or about right? Dishwasher on a septic system? I don’t think really matters. If I had a dishwasher – I’d run it into a disposal even if I did not use the disposal for anything else.

Q – 10 What is Garbage Disposal Repair?

Ans- Garbage Disposal problems can be plumbing, electrical or appliance. If the disposal doesn’t work at all – no *hum* or any sound, then push the red (reset) button on the bottom of the disposal. If that doesn’t work, check the breaker in the electrical panel. If the unit *hums* but doesn’t turn then you can try unsticking it.. Some units come with a wrench that you can use to turn the cutter flywheel from the bottom.

( An allen wrench will work). Or, use a *plumber’s friend* , broom handle- something with a handle, and stick it in the disposal and try to turn the cutting wheel around. In effect – unstick it. If the unit doesn’t respond to the above, it’s time for an appliance repair man or replace the unit.

Q – 11 What is Leaking Steel Union?

Ans- In WA State gas unions are not allowed inside buildings. There are left and right hand couplings and nipples that take the place of unions. No sealant is required on unions faces – the seal is made by the beveled male/female surfaces. Also do not use regular teflon tape. There is a separate type of tape for gas. Really, I think TU555 is the best sealant.

Q – 12 Will Natural Gas Corrode Galvanized Pipe?

Ans- In the old days, sometimes after a long time. This was generally due to the poor quality of galvanizing. Today using galvanized pipe generally presents no threat. Plumbers tend to use black pipe with gas for two main reasons. One is that it costs less than galvanized (except I’ve seen some home centers charging more for black which must be because of consumers lack of knowledge of “cost”).

The other is that if galvanized pipes are used for water then using black for gas distinguishes the two uses. Imagine using galvanized for both gas and water in the same house? That could present a problem in people distinguishing which pipes are carrying what. I like to suggest painting galvanized pipes used for gas yellow. Today there exists flexible stainless steel gas pipe and it always yellow (that I’ve ver seen) so painting piping that is for gas yellow seems like a good idea.

If pipe is in the ground it will tend to corrode faster (depends on the soil conditions). Many areas do not allow galvanized pipe underground for gas piping and factory coated steel pipe must be used. In some areas plastic pipe is allowed underground (with electric wire above it to allow for locating of that plastic gas pipe as well as warning tape above that pipe as well).

Q – 13 Is Replacing a Tub a Big Job?

Ans- It is a JOB. A couple of suggestions… while you’re at it replace the waste and overflow and if possible the tub/shower faucet. Second, you can get tub surrounds in two pieces that will fit through doors and Three (I like the Sterling brand surrounds), American Standard makes an *Americast* tub that has the properties of a cast iron – but without the weight.

I personally prefer Kohler cast iron over Americast as I think it’s more durable. BTW you can break out the old cast tub with a sledge hammer and cut up a metal tub with a Sawzall all.

Q – 14 Adding a new Drain to Cast Iron Pipe Where There is a Cleanout?

Ans- A couple of ways to go. That *little rect. box* is a cleanout plug. It’s brass. If you can unscrew it great – if not cut – off the square with a Sawzall- all and you will find that it’s hollow. Then cut from the center out to the threads in pie sections. Peel the plug out of the female threads.

If you’re lucky it will be 3″. Screw in a 3″ male adapter and kick on out… However it may be 3 1/2″ which is no longer made. Use a 5″ by 3″ Fernco bell with the 5″ over the hub of the cleanout. Bush down with a 3″; by 2″bush in the 3″ end of the Fernco and your home again. The other way is to take a section out of the cast pipe, use Fernco’s around a PVC or ABS Sanitary Tee (whatever your state uses).

That *6″ iron pipe* is most likely 4″ cast. You can cut it with a Sawzall-all or snap it with a *rachet cutter* that is made to cut cast iron. I bought one for $340 – so you might want to rent or beg/borrow one. BE SURE that if you take a section out of the cast, that the upper section of the pipe is supported so whole thing does not come crashing down.

Q – 15 What is Cutting Cast Iron and Plastic/Cast Connections?

Ans- You cut the cast iron with a reciprocal saw like a Milwaukee Sawzall all. Use heavy metal blades like Lenox 614R type. I start with the six inchers. It will take several to get through the side of the pipe . Once you have made a cut into the pipe – it will go faster. You’ll need the long metal blades to finish the job. At first-it will seem like it will never cut it-but it will. Use Mission or Fernco No Flex couplings- one on each side-to connect the plastic and cast iron. Do not forget the vents!

In most situations I use a Ridgid rachet cast iron cutter on iron waste pipes, but sometimes conditions are too confined to use that tool.

Then I use a mini-grinder with a diamond wheel (they’re $100 each but one lasts a lifetime) to cut as much as I can reach with that tool and finish the cut with the sawzall and a grit-edge blade. BTW the grinder with the diamond wheel is terrific for cutting tile, concrete and brick. A little dusty though.

Q – 16 I need basic plumbing repairs in my home to fix a leaky faucet or clear a clogged drain. Is this what a plumber does?

Ans- Yes! A plumber is a highly skilled worker who installs and repairs pipes and plumbing related fixtures, diagnose clogged drain problems and solves all problems related to water systems in your home. At Blue Mountain we’re dedicated to continued training and education in the latest plumbing techniques and tools to provide the highest quality work for our customers.

Our plumbers not only receive technical training but we are the undisputed leaders in customer service training. This means you are guaranteed a courteous, professional and friendly plumber at your door, every time!

Q – 17 How do I clear my clogged garbage disposal?

Ans- You may be able to insert an Allen wrench into the bottom of the disposer and “crank” it to help free up a jam. If this doesn’t work, DON’T USE IT! You could cause serious damage to the disposal motor or even your home electrical system. Blue Mountain can usually fix a jammed up garbage disposal. If we can’t, then the unit will probably need to be replaced. Our expert technicians can give you the best advice and make quick work of it to get you grinding again!

Q – 18 What is Repairing (garden) hose bibbs?

Ans- IMHO unless the HB is new enough to match the insides with the exact same brand, model et – replace the darn thing. You can try , but , I just don’t seem to have permanent success when I just repair them. Now to replace them- if they come through the wall under the house then they can be unscrewed or unsoldered from the crawl space. If it is above the floor a *window* has to opened in the wall. Just unscrewing it from outside will often result in a broken pipe in the wall.

Q – 19 What is Claw Foot Tub Faucets?

Ans- These faucets are special to CFTs they have 2 3/8″; centers. Some units have 1/2″; and some have 3/4″; water connections at the back. The 3/4″; needs special CFT supply pipes. Most older faucets are not code and it is still easy to buy non-code faucets. The code is that the faucet spout must have a gap of at least 1″; between the top of the tub rim and the bottom of the spout – that’s so bath water in the tub cannot siphon back into the drinking water supply.

Q – 20 What is The Faucet CLUNKS When We Turn It On?

Ans- 99% of the time when you hear a clunk in any pipe when you turn a faucet on/off – it’s a loose washer in the faucet. When you take it apart be sure you get the old washer and a screw. If you don’t – turn the water back on and flush out the missing part.

Q – 21 What is Delta Faucet Repair?

Ans- You can buy a Delta single handle faucet repair kit with a tool for maybe five to seven bucks. It has all the instructions and is very easy to do.

Q – 22 What is Moen Faucet Repair?

Ans- Moen faucets have cartridges that can be replaced. There is a clip (on top) that has to be pulled up and out before the cartridge can be replaced. Often it seems stuck as if it will not come out. Some replacement cartridges provide a plastic square to turn the cartridge in the valve body 1/4 turn. This breaks it free from the valve grease that it is stuck in. If, after replacing the unit ,the hot and cold are reversed, re-install with the cartridge turned 180 degrees.

Q – 23 Connect Sump Pump Outflow to Septic?

Ans- It is illegal to connect any rain or ground water to the sewer. IF, however, you do hookup – at the very least put a trap in the in the line to keep sewer gas out of the house.

Q – 24 Leak Somewhere in the Plumbing in my Shower/Bath?

Ans- I see this all the time and nine times out of ten its the grout or a bad pan under the shower. Before anything else I try to determine if the leak is constant or if it is periodic. If it is constant there is a good chance the leak is in the pressurized water lines.

Usually the leak is periodic so I have a series of tests that I perform to track it down. Sometimes a quick visual inspection of the tile will show that the grout is shot and is the most likely cause of the leak but I will often complete the rest of my tests to be sure. What I do is first fill the tub half way and drain it. This will tell me if it’s in the drain pipe. For a shower with a lead or vinyl pan I block the drain and fill the base with water.

This will tell me if the pan leaks. Then I remove the shower head and put a 1/2″ cap on the shower arm and turn on the pressure. This will tell me if there is a leak in the pipe between the shower valve and the shower arm. If no leak has shown up by then I tend to think the leak is water bleeding through the tile due to bad grouting or that water is escaping the shower and going down through flaws in the bathroom floor.

I can check this by taping up a plastic dropcloth inside the shower covering all the tile work and having the customer use the shower normally for a day or two. If the leak has suddenly disappeared then we know it coming through the tile. A few cups of water on the floor will show a leak through bad tile or a cracked floor base.

Q – 25 Can Clogged Vents Stop Up Drains?

Ans- Yes and no. A toilet with no vent may not flush the contents out of the bowl, but any other drain will work without a vent.

(NOTE: the code is that all fixtures shall be vented). Only twice in 15 years has the vents been the cause of a drain backup. In one case it was roofers who stuffed the old roofing material down the vents and the other was just a stray piece of wood. In both cases the material made its way down into the drain pipe and had to be removed. No amount of *vent cleaning* would have done any good.

Q – 26 Leaking Bathtub Drain Right at the Drain Hole?

Ans- It is replaced from the top, that is sitting in the tub. Hopefully you have *crosshairs* or a couple of little *nibs* inside the drain flange (the chrome part). That’s the part that unscrews. The tool is called a *pickle* – it has a fork at one end and crossed slots at the other.

Or a *dumbell* which is tapered and has crossed slots at both ends. Or just use pliers and stick the handle end down into the drain, catch the cross hairs or nibs and unscrew. Clean off the old plumbers putty. Slide a new washer between the underside of the tub and the *shoe* (part with female threads) and put putty around the chrome flange and screw it back in.

Q – 27 Do Unused Drains Dry Up and Get Rough Inside?

Ans- Yes, drain pipes do dry out and get real rough. Will it clear up with use? Maybe.

Q – 28 How Do I Get A Snake Down a Tub Drain?

Ans- To get a snake in the drain you take off the *overflow plate*. That’s the chrome thing on the tub wall with two screws. When you pull it out – two sections of the stopper mechanism will come with it. It’s hinged so it will bend through the hole. Chances are that hair caught on the end of this mechanism is clogging the drain- you might not even need to snake it. BTW – A snake will not go through the drain hole at the bottom of the tub.

Q – 29 When I Run The CWM My Toilet Bubbles/Overflows or My Shower Overflows?

Ans- The washing machine line could be connected to close to the “suds rinse zone”, meaning the washer waste ties into the waste or soil line of another fixture to close downstream from the problem fixture. What is happening is the water is rushing by the suds at a high velocity, pushing ahead of the suds. Because the fixture is the closest place of relief, the suds will come up into the fixture, even a toilet.

The code requires that a washing machine, kitchen sink, shower, and dishwasher line be connected at least 5′ downstream from any fixture branch. This could be just one of many possibilities for the bubbling and backup.-Bill Dwight,

Q – 30 When I Run The CWM My Toilet Bubbles/Overflows or My Shower Overflows?

Ans- When the lowest plumbing fixture in the house overflows when another fixture (like a CWM) is draining; the septic tank needs to be pumped, there is a break in the sewer pipe outside the house or the main drain is plugged somewhere.

Q – 31 How do I know if I have a broken water line outside my house?

Ans- A broken water line out in the yard may include an excessively high water bill, puddles in your yard or the sound of running water when no faucets or appliances are using water. Blue Mountain can pinpoint the problem without needless trial and error destruction of working pipes. In many cases we can fix the problem right away and save you money.

Q – 32 What is the most common reason for sump pump failure?

Ans- The leading cause for sump pump to failure is usually a switching problem. Sometimes the pump can move inside the basin. This movement causes the float that operates the switch to lodge against its side. Debris can also be a factor by interfering with the action of the pump switch.

It is important to make sure that your pump switch and float arm assembly move freely. The main thing to remember about sump pumps is that they don’t last forever…even if you never use them. Internal part wear out and make them virtually useless when you need them most! Blue Mountain can test, maintain or replace any brand of sump pump.

For flood-prone areas and homes that get water seeping in on a regular basis you may want to consider a sump pump back up system. There are even non-electric systems that work in the case of a power failure. Call Blue Mountain for more information.

Q – 33 Sealing the W/C tank to the Bowl?

Ans- Get the best results by using the large donut gasket of the type that is square cut inside to match the shape of the nut on the bottom of the tank. Sealant will not help. Tighten the bolts down evenly to the point where the tank is snug on the bowl. Over tightening will break the bowl and/or tank.

Q – 34 High Pressure Makes My Toilet Run (with new ballcock)?

Ans- If your water pressure is so high that it leaks past a Fluidmaster 400A or another new ballcock (aka: “toilet fill valve”) – then you NEED a pressure reducing valve. Other water pipes, connectors, clothes washing machine hoses and your water heater could leak or break. Best to get a pressure regulator if your pressure to the house is more than 60 pounds (80 is code throughout most of the U.S.).

Q – 35 Toilet Leaks at Base in Moved Toilet Location or New Floor Install?

Ans- Is the top of the flange even (or close to even) with the finished floor? If it to low – then use two wax rings. One regular wax ring on the bottom and one (or more) with the plastic horn insert on top. ) I have seen leaks like you describe if the glued flange is not really glued in all the way. Take a look at that – if your floor and flange is flush. Sometimes you need to shim the toilet if the floor is uneven or the flange is to high.

Q – 36 Explain Low Flush Toilet Problems?

Ans- You might buy a better flushing toilet for your situation. Some air assisted toilet flush well. When the low gallonage gravity toilets first came out I replaced a couple of new Kohler Wellworth Lites with the Am.Std. air assist toilet with good results.

That was then and this is now. Today most brands of gravity toilets flush well (including the redesigned Kohler Wellworth models). Power assisted toilets tend to be noisy and frankly, today I definitely do not recommend power assisted toilets.

By the end of 1999 (most brands of U.S. made) gravity toilets manufactured were flushing fine. At the end of 2000 my guess is that over 85% of 1.6gpf toilets flushed well.

Q – 37 What is Gas HWT Height?

Ans- Gas HWT have to be at least 18″ off the floor because combustible fumes *sink* and for air intake.

Q – 38 On demand hot water system?

Ans- The relative energy efficiency of these systems depends a lot on other factors such as the amount of heat loss from a more traditional storage tank system or the length of time hot water is stored before it is used. In practice they require a good deal more energy per volume of heated water than conventional systems and they cannot usually provide enough hot water for more than one fixture at a time. The traditional storage tank type of water heater can be quite efficient if the tank and the hot water pipes are properly insulated.

The on-demand type heaters have their uses in the appropriate situation. I have found them practical and efficient in situations where hot water is used only occasionally such as in some shop situations or where a fixture is at a considerable distance from a traditional storage tank water heater, such as in a guest house or pool house. They can also be handy if you are adding hot water to a structure that has been cold-water-only and the cost or inconvenience of adding a complete hot water piping system will be prohibitive.

Q – 39 If I have need Rooter Service, do I have to call one of those national rooter chains?

Ans- No. We would recommend that you call a qualified, trained and certified plumber. Why? The water pipes inside and outside your home can be very delicate. In an older home, pipes wear thin from the inside out making them appear sound but in fact are very brittle. An unqualified and unskilled rooter company could cause extensive damage to your pipes and your home.

The highly trained and certified technicians at Blue Mountain will take the time to properly diagnose the problem and utilize the right tools and techniques to solve the problem. Should there be an issue of a broken pipe or other unforeseen problems after we begin the job, our expert plumbers can immediately take action. Can the other guys? We’re not sure…and we don’t recommend that you take a chance.

Q – 40 Is there really a difference between hard water and soft?

Ans- Yes. In fact, the difference can be damaging to your home and your body. Maybe you have experienced damaged clothing from the laundry, excessive soap consumption, pipe scaling, faucet and fixture deterioration, skin problems, or undesirable tastes or odors from your water. If you have, then you have a water problem. Call Blue Mountain for expert advice on all kinds of water treatment systems.

Q – 41 Explain Conventional Water Heaters vs. Tankless Water Heaters?

Ans- Conventional water heaters are by far the most common type of water heater in the U.S. today. They range in size from 20 to 80 gallons (or larger) and are fueled by electricity, natural gas, propane, or oil. Called ‘storage’ units, these water heaters transfer heat from a burner or coil to water in an insulated tank. The down side to a conventional water heater is that energy is consumed even when no hot water is being used.

Tankless water heaters do not contain a storage tank like conventional water heaters. A gas burner or electric element heats the water only when there is a demand for hot water.

There are many things to consider when choosing conventional vs. tankless water heating systems. Your Blue Mountain representative can guide you through your options and get the right system for home that will give years of service and efficient performance.

Q – 42 Water Heater Maintenance?

Ans- 1.) Turn off electric power or gas before doing anything. Damage will result if element comes on when tank is dry. Turn of water supplying HWT. Note that a time switch is NOT a safe place to turn off the electricity! Do it from the circuit breaker, or pull the fuse.

2.) Drain the water heater (HWT). After HWT is drained, and hose is still attached, open and close the inlet valve a few times to help flush the sediment out. Do this ’till the water comes out clear. You may have to dismantle the valve, if there are large chunks of scale coming loose.

3.) Remove the sacrificial anode, which looks like a plug in the top of the HWT. Inspect; it should be almost as long as the water heater. Replace if any portion of it is thinner than about 1/4″;.

4.) With anode out, shine flashlight inside of tank to inspect for rust. If you see a lot of rust, it’s probably time to replace it…before it fails. Water heaters are normally glass- or ceramic-lined to prevent corrosion; this is also what the anode’s for. The heat of the water hastens corrosion, once it starts.

5.) Open up the element access panels. Disconnect one wire from each of the elements. With a volt-ohm-meter, check to see that both elements are still functional (the resistance across the terminals should be ??? ohms, but if your meter peaks out with exceptionally high ohms, it’s time to replace the element).