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Changing the hot water mixing valve

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  • Dec 18th, 2019 4:55 am
[OP]
Jr. Member
Feb 12, 2008
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Toronto

Changing the hot water mixing valve

Hi,

The showers in my house were not delivering hot water quickly enough, so I called the rental water heater company -Reliance- to take a look. I was told that the mixer valve of the water heater is not functioning properly and I should get it replaced. Apparently Reliance is not responsible for that part.

1. Do I have to get a new mixer valve or can I clean the existing one and put it back?
2. Can an average person do this kind of job or is it a specialized task of a plumber?


i am generally good with such tasks and have all necessary tools.
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Almost all problems in our lives can be traced back to a lack of knowledge.
33 replies
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Feb 11, 2007
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musicgold wrote: Hi,

The showers in my house were not delivering hot water quickly enough, so I called the rental water heater company -Reliance- to take a look. I was told that the mixer valve of the water heater is not functioning properly and I should get it replaced. Apparently Reliance is not responsible for that part.

1. Do I have to get a new mixer valve or can I clean the existing one and put it back?
2. Can an average person do this kind of job or is it a specialized task of a plumber?


i am generally good with such tasks and have all necessary tools.
First off, don't trust anything Reliance says, they have pretty sleezy tactics.
Did they actually come take a look?
Do you eventually get very hot water when requested?
Have you confirmed that you actually have a mixing valve?
What temperature is the hot water tank currently set at?
How old is the tank?

If you can solder than you can do it.
[OP]
Jr. Member
Feb 12, 2008
165 posts
13 upvotes
Toronto
engineered wrote: First off, don't trust anything Reliance says, they have pretty sleezy tactics.
Did they actually come take a look?
Do you eventually get very hot water when requested?
Have you confirmed that you actually have a mixing valve?
What temperature is the hot water tank currently set at?
How old is the tank?

If you can solder than you can do it.
1. Reliance had sent their man to take a look and he told us about the problem. He told us that the water temperature at the heater is 120 degrees but it drops to 108 degree at the valve.
2. He showed us the valve.
3. Yes, hot water comes eventually.
4. The tank is 15+ years old, I think.
5. If it needs soldering, I can't do it. I thought it involved just using the spanner. I have fixed drain clogs and changed faucets.
Images
  • Water heater mixing valve.jpg
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Oct 15, 2007
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musicgold wrote: 1. Reliance had sent their man to take a look and he told us about the problem. He told us that the water temperature at the heater is 120 degrees but it drops to 108 degree at the valve.
2. He showed us the valve.
3. Yes, hot water comes eventually.
4. The tank is 15+ years old, I think.
5. If it needs soldering, I can't do it. I thought it involved just using the spanner. I have fixed drain clogs and changed faucets.
The water in the tank should be at 140, And then mixed down to 120 at the mixing valve. If it’s currently only at 120 in the tank then it is set too low and Legionella can/will form.
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide
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Feb 11, 2007
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musicgold wrote: 1. Reliance had sent their man to take a look and he told us about the problem. He told us that the water temperature at the heater is 120 degrees but it drops to 108 degree at the valve.
2. He showed us the valve.
3. Yes, hot water comes eventually.
4. The tank is 15+ years old, I think.
5. If it needs soldering, I can't do it. I thought it involved just using the spanner. I have fixed drain clogs and changed faucets.
Looks like you have plastic PEX piping, so should just be spanners. Just make sure to do it right.

That said, with a 15 year old tank, you should look at giving reliance back their tank and installing your own, so you're not paying their wasteful fees.
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Apr 26, 2013
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engineered wrote: Looks like you have plastic PEX piping, so should just be spanners. Just make sure to do it right.

That said, with a 15 year old tank, you should look at giving reliance back their tank and installing your own, so you're not paying their wasteful fees.
My thoughts exactly.
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Nov 1, 2010
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You can also completely remove the mixing valve and go without. You get a real nice HOT water that way. I've done it, relatively simple. Also if it's 15 years old and you're still renting, maybe look into getting a new tank like they said above.
Uh, yeah, I'd like to speak to a Mr. Tabooger, first name Ollie.
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Tabooger wrote: You can also completely remove the mixing valve and go without. You get a real nice HOT water that way. I've done it, relatively simple. Also if it's 15 years old and you're still renting, maybe look into getting a new tank like they said above.
At least warn OP that this would be against code and will increase the chance of scalding
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide
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Feb 11, 2018
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OP find out how much to buy the tank and put an end to wasting money on rent. At 15 years it wouldn't hurt to replace the tank. Buy your own and have it installed by a third party.

Regarding the mixing valve, I removed mine. People in my house know how to handle hot water. I always mention it to my guests that hot water is at 140F.

Red_Army wrote: At least warn OP that this would be against code and will increase the chance of scalding
Driving at 101km/h where the speed limit is 100km/h is also against code and it does increase the chance of having an accident ;)
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TomLafinsky wrote: OP find out how much to buy the tank and put an end to wasting money on rent. At 15 years it wouldn't hurt to replace the tank. Buy your own and have it installed by a third party.

Regarding the mixing valve, I removed mine. People in my house know how to handle hot water. I always mention it to my guests that hot water is at 140F.




Driving at 101km/h where the speed limit is 100km/h is also against code and it does increase the chance of having an accident ;)
Yes I’m sure that most people are aware of that. They may not be as familiar with plumbing codes and scald rates however, and may have to re-install when selling their home
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide
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Red_Army wrote: Yes I’m sure that most people are aware of that. They may not be as familiar with plumbing codes and scald rates however, and may have to re-install when selling their home
Do you remember when (what year) mixing valves became mandatory?
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TomLafinsky wrote: Do you remember when (what year) mixing valves became mandatory?
‘04 I Believe
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musicgold wrote: 1. Reliance had sent their man to take a look and he told us about the problem. He told us that the water temperature at the heater is 120 degrees but it drops to 108 degree at the valve.
2. He showed us the valve.
3. Yes, hot water comes eventually.
4. The tank is 15+ years old, I think.
5. If it needs soldering, I can't do it. I thought it involved just using the spanner. I have fixed drain clogs and changed faucets.
ask what buyout ( I would guess it would be less than $100 ) is. Buy it out and replace the dip tube ( which will resolve your issue ) and the Anode ( to keep it working longer).
TomLafinsky wrote: Regarding the mixing valve, I removed mine. People in my house know how to handle hot water. I always mention it to my guests that hot water is at 140F.
I think I already explained to you, there is 0 benefit in not having a mixing valve.
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Red_Army wrote: Yes I’m sure that most people are aware of that. They may not be as familiar with plumbing codes and scald rates however, and may have to re-install when selling their home
Not to mention the potential hazard if you have younger children, even the elderly can experience severe issues when scalded.
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Red_Army wrote: ‘04 I Believe
My original tank didn’t come with such a valve and the plumber never installed one when the tank was replaced in 2009. Grandfathered?
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mrweather wrote: My original tank didn’t come with such a valve and the plumber never installed one when the tank was replaced in 2009. Grandfathered?
Nothing grandfathered unless your tank is still in service from 04 or before, just a lazy plumber
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide
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The mixing valve goes bad every a few years because of sediment builtup.

You can remove it. The hot water temperature can be adjusted at the tank side. No need for such a fitting that only enriches plumbers.
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Supahhh wrote:
I think I already explained to you, there is 0 benefit in not having a mixing valve.
For one thing, given it retails for about $100 and it tends to fail after a few years, you can save yourself a tiny amount of money by not having one ;) But the reason why I removed it is that it introduces inefficiency in the system and I have zero desire to explain this to those who don't understand it.
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TomLafinsky wrote: For one thing, given it retails for about $100 and it tends to fail after a few years, you can save yourself a tiny amount of money by not having one ;) But the reason why I removed it is that it introduces inefficiency in the system and I have zero desire to explain this to those who don't understand it.
I will try to explain again. you dont need to reply if you disagree. It might help other understand how it works.

How it works:
  • Hot water at 140 comes from your tank and you mix with cold water at the shower to bring it to 90-100.
  • A mixing valve does the exact same thing, it mixes hot water at 140 down to 110-120 or so by mixing in some cold water. The water heater is unaware that anything has changed.


Advantages:
  • With A mixing valve you can set water heater to 160F and yet have safe water temperature of 110F. By doing so you increase the stored capacity of hot water by 10-15% ( this is the same as going from a 50Gal Tank to a 60Gal tank ).
  • By running the plumbing lines at a cooler temperature, you reduce line heat losses ( since they are dependent on the differential temperature ).
  • ofCourse the lower temperature is safer in case someone accidentally opens the hotwater only.


Maintenance:
  • Mixing Valves malfunction due to carbonate builtup.
  • If you have a water softener this is unlikely to happen for a long time.
  • Buy mixing valves with teflon elements.
  • If your mixing valve is malfunctioning , you can take it apart and clean it ( with CLR or vinegar and a brush ) or buy a kit instead of a new valve. Good valves should last 5+ years and even longer with a water softener( or if you have softwater to begin with as most of GTA has ).
Last edited by Supahhh on Dec 18th, 2019 2:59 am, edited 3 times in total.
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sherwoodRFD wrote: The mixing valve goes bad every a few years because of sediment builtup.

You can remove it. The hot water temperature can be adjusted at the tank side. No need for such a fitting that only enriches plumbers.
Enjoy Legionnaires disease or scalding water if you do it this way
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide

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