More Shut-off Valve Problems...

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pakle

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So an update on my attempt to get all my 14 toilet & sink shut-off valves replaced with Dahl-brand as recommended in a previous thread here:
https://www.plumbingforums.com/thre...-for-toilet-sink-other-than-home-depot.17808/
I was scheduled to have my handyman out here today but an emergency came up and he sent his son, who has done a lot of work with him on my home as well, including changing some of those shut-off valves last year. 2 big problems came up:

1) Shut off main water shut-off, which is gate type. It could not shut off all the water supply, the faucets would all run dry, but water still spilling out of the valve under sink. The son doesn't know what's wrong with the gate valve, so will have to get his Dad out here to look at it.

BACKSTORY: After the main shut off gate valve leaked slightly last year, I had the handyman try to change it out but he couldn't get the nut off in the drywall (see picture) so he assured me that it was okay to just change the blue handle and gasket. I hate the gate valve and really wanted quarter turn but that would've required cutting a big hole in the drywall to access and probably moving the water heater. He told me any leak would most likely be at the nut which I would see right away on the drywall, or on the valve itself, so I relented.

QUESTION: Why would the gate valve not shut off all the water? It gets enough 'exercise,' handle & gasket just got changed about 7 months ago. Never had problem shutting off water completely for changing valves in the past years before 7 months ago. In general, we shut off water to the whole house when we go on vacation which is at least a couple times a yr in non-covid years.

2) So the son proceeds with removing the shut-off valves under the sink because I need the kitchen sink faucet replaced as well. Buckets & towels underneath to catch the water. The cold water shut-off valve has been leaking less than a drop a day for who knows how many months AND it was already replaced exactly a year ago as described in the thread linked above with the Brasscraft from Home Depot. He puts in the brand-new Dahl valve... AND it continues to leak! The ferrule is tight. The hot water & dishwasher shut-offs do not leak (so far) when replaced with Dahl. So assuming very unlikely the brand-new Dahl is defective, we are thinking the copper pipe for cold water has been deformed by all the valve changes (5 yrs ago, 1 yr ago, today). He didn't have the pipe-cutting tool (Dad had it) so he'll have to come back. I told him let's not do any more today because it's too watery messy and it's best anyway to get Dad to fix the main shut off so the water is *completely* shut off and then change the rest of the 11 valves+1 leaky cold valve.

QUESTION: Since I had so much trouble with leaky valves last year and the ones that don't actively leak have the green deposits as mentioned at the end of the previous thread, should I be assuming most/all of the rest of the copper pipes have been deformed? Should they be cutting off an inch on all of them before putting in the new valves to start on newish copper? Can you tell/not tell just by looking at the copper pipe?

Part of me wishes I never embarked on this valve-changing exercise, it's certainly expensive and stressful...
 

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Gate valves do not seal with a gasket. They seal with a metal gate that rises up and down. I only use a gate valve if it’s absolutely necessary and that’s almost NEVER.

You need good pipe to connect the new valves to.

I suggest calling a professional plumber if you’re not going to DIY. Does your handyman have insurance ?
 
Gate valves do not seal with a gasket. They seal with a metal gate that rises up and down. I only use a gate valve if it’s absolutely necessary and that’s almost NEVER.

You need good pipe to connect the new valves to.

I suggest calling a professional plumber if you’re not going to DIY. Does your handyman have insurance ?
I know he cannibalized 2 things from the new gate valve package, one being the handle, and I thought the other was a gasket. If not a gasket, I don't know what but the new handle is harder to turn than the old one.
 
The parts he replaced don’t shut the water off. Looks like he replaced handle and packing/nut...
Yes that sounds right. Any idea why that would cause the water not be able to shut off completely now? Just a bad coincidence?
 
I typically solder all my stop valves on . This eliminates a few possibilities and remedies a few problems.
 
It has to fail sometime......
It was leaking at the packing nut last year (a drop every few days) after my remodel last Jan. He tightened the packing nut at the time to get it to stop leaking, but I thought I was being proactively by trying to get the whole thing replaced 7 months ago. Looks like I made the problem worse...

Maybe it's time to bite the bullet and get a plumber to cut the big hole in the drywall and move the water heater to put in the quarter turn... tired of this.
 
One old trick when working on a fixture or valve that won’t fully shut off, is to open up other faucets to let water pressure out there instead.

Especially a lower faucet or fixture.

If your water heater or slop sink is lower in the house, or closer to the main shutoff, opening either or both of those would probably stop the slow flow at the valves you are trying to replace.

Sometimes, putting a thin coating of pipe dope under the ferrule contact point, and a little more around the ferrule, will solve a very slight compression leak.

If the valve body can be at all rotated afterwards, don’t trust it.
 
One old trick when working on a fixture or valve that won’t fully shut off, is to open up other faucets to let water pressure out there instead.

Especially a lower faucet or fixture.

If your water heater or slop sink is lower in the house, or closer to the main shutoff, opening either or both of those would probably stop the slow flow at the valves you are trying to replace.

Sometimes, putting a thin coating of pipe dope under the ferrule contact point, and a little more around the ferrule, will solve a very slight compression leak.

If the valve body can be at all rotated afterwards, don’t trust it.
We tried leaving all the other faucets open, both upstairs & downstairs, hot & cold. Water never shut off fully, even after an hour, and it was still very messy.

Son talked to Dad tonight and Dad said he was supposed to shut off hot water heater valve (see pic, top knob next to expansion tank) as well as main shut off. We had thought about this but thought it was for hot water only at the time, I guess none of us paid attention to how the water was shut off for valve changes previously. Will try shutting both valves tomorrow and waiting an hour, and let you know. Done for today.

Jeff: Do you recommend putting the pipe dope around the ferrule for the small leaks vs. cutting off an inch of copper for those that have had several valve changes on the same piece? That cold water valve has leaked maybe 4 drops in the bucket over the past 6 hours. Or this may be one of those "depending on experience" questions...
 

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We tried leaving all the other faucets open, both upstairs & downstairs, hot & cold. Water never shut off fully, even after an hour, and it was still very messy.

Son talked to Dad tonight and Dad said he was supposed to shut off hot water heater valve (see pic, top knob next to expansion tank) as well as main shut off. We had thought about this but thought it was for hot water only at the time, I guess none of us paid attention to how the water was shut off for valve changes previously. Will try shutting both valves tomorrow and waiting an hour, and let you know. Done for today.

Jeff: Do you recommend putting the pipe dope around the ferrule for the small leaks vs. cutting off an inch of copper for those that have had several valve changes on the same piece? That cold water valve has leaked maybe 4 drops in the bucket over the past 6 hours. Or this may be one of those "depending on experience" questions...
Daddy’s wrong......that main valve should’ve shut it down, the water heater should siphon for a few minutes then stop.
If not, there is a problem. But sure, shut all the valves it can’t hurt,Unless when you open them the gate comes off......
 
If you shut any valves on the water heater, make sure the gas valve is off first.

If you have enough copper to be able to cut to fresh metal, that is best way.
 
If you shut any valves on the water heater, make sure the gas valve is off first.

If you have enough copper to be able to cut to fresh metal, that is best way.
It’s really not necessary to turn the water heater to pilot when turning off the water. Especially if you have thermal expansion control OR simply let the pressure off th hot side by opening a faucet.
 
He was also going to close the hot outlet valve.
And maybe the cold inlet, I forget now.

So the heater should be off, IMHO.

Easy to do, and when shutting all kinds of misc valves, why not just be extra safe.
 
He was also going to close the hot outlet valve.
So the heater should be off, IMHO.

There shouldn’t be a hot outlet valve. All you need on a water heater is the cold inlet stop valve.

Turning the power or gas off to a water heater because the waters off is not necessary for up to a couple weeks.....

Who told you different and why ?
 
Many states allow them, I know, dumb, right!
Very handy during servicing or heater swap out, also very dangerous.
 
Many states allow them, I know, dumb, right!
Very handy during servicing or heater swap out, also very dangerous.

A valve on the hot side is pretty much useless.
It’s not really dangerous unless other things fail.....at least two other things....Plus open valves wouldn’t help if those other safeties failed.....

The high limit would need to fail along with the temperature and pressure relief valve. Plus the thermostat would need to also stick in the heating position........

Now would open valves help-if all those failed ? Not one bit......
 
If all those things failed, and the hot outlet valve was open, I think a faucet cartridge with rubber seals would start blowing hot water or steam, before the heater blew up.

Anyway, bed time for me!
 
Some people think a thermal expansion tank protects the heater from exploding violently. Not the case.

It protects against over pressuring the water heater and the plumbing system as a whole.

However, uncontrolled thermal expansion can damage a water heater and with a gas water heater it can damage internal flue and it can cause carbon monoxide to spill. Rare but possible. A Rheem unit wouldn’t do it.....TRD would shut it down almost immediately.
 

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