Mixing valve issue or something else?

NickB2005

hey all, so lately I would say the last couple months 2 or so my shower needs to be turned all the way around to even get warmish/hot for a few water, but it never use to be like that. I would be able to turn it 3/4 of the way and get nice hot steady water for 10-15 minutes in the shower which is all I take.

So, I was checking the Honeywell AMS mixing valve next to my water tank and I turned it all the way and the sink water upstairs gets piping hot, the hot pipe is extremely hot, the cold is cold, but where it mixes and goes up that was just warm or I should say not enough where I couldn't put my hand on it and hold it.

This heating system is brand new was just put in Nov 2016. I wasn't sure if it's been the extreme cold weather we've had in Boston the last few weeks either, but then it's been kind of warm the last weekend or so.

My plumber who installed it, I called him, he's awesome told me to basically turn on the water in the sink upstairs and then turn the mixing valve till it gets hot and it does. The other day the sink water temp was 105 and same with the bathroom.

I am not really sure what else to try as the shower in the bathroom is brand new too, all the piping, valves, etc was put in Jan 2017.

Any help would be appreciated and thank you in advanced.

hot_rod

Can you get a strap on thermometer and get some actual readings?

The hot entering on the H side needs to be about 20- 25 degrees hotter than the mix temperature you desire.

Typically 120 mix is what they get set for. So your hot supply from the tank would like to be 140°F or hotter to get a good stable supply from the max valve.

Depending on the type of valve it may require .5 gpm or more to mix accurately also. So if you just run a trickle from a lav faucet there is not enough flow around the thermostatic mix device for it to respond properly. Open a tub or high flow faucet and check the temperature.

Generally you get a varying temperature under either of these conditions, warm, hot, cooler etc. Called a thready mix, sometimes.

A hardware store should have some stick on, strap on or sensor type temperature gauges.

Jean-David Beyer

When I had a mixing valve installed so I could run my indirect hotter (at least 140F), I had a well installed where the hot entered the mixing valve, and another well installed where the mixed water left the mixing valve. I had thermometers installed in those wells. Considering the cost of the valve and some related plumbing improvements, and the labor and profit for the plumber, the cost of the wells and the thermometers was unimportant. My mixing valve even came with a stick-on temperature gauge, but it would not do long-term, and the dial thermometers seem to be more accurate.

NickB2005

hot rod said:

Can you get a strap on thermometer and get some actual readings?

The hot entering on the H side needs to be about 20- 25 degrees hotter than the mix temperature you desire.

Typically 120 mix is what they get set for. So your hot supply from the tank would like to be 140°F or hotter to get a good stable supply from the max valve.

Depending on the type of valve it may require .5 gpm or more to mix accurately also. So if you just run a trickle from a lav faucet there is not enough flow around the thermostatic mix device for it to respond properly. Open a tub or high flow faucet and check the temperature.

Generally you get a varying temperature under either of these conditions, warm, hot, cooler etc. Called a thready mix, sometimes.

A hardware store should have some stick on, strap on or sensor type temperature gauges.

I was looking at like Lowes or Home Depot and I don't really see which item would be best to go get. Would I strap on the thermometer where the mixing valve pipe goes up? Like where it comes together? I don't have one, but I am sure I can go buy one or something at the local store. The H coming in side is definitely way hotter than the actual pipe from the mixing valve. To the point where you can't put your hand on it for more than a second or two.

unclejohn

Is the shower a self regulating temp kind? Maybe your mixing at the shower as well.

NickB2005

> @unclejohn said:
> Is the shower a self regulating temp kind? Maybe your mixing at the shower as well.

Sorry, I’m not that smart. I apologize. What does that Mean? Or better yet how would I tell?

unclejohn

http://homeguides.sfgate.com/replace-shower-mixer-valve-102141.html

Ask who ever installed the shower fixture if it's this type.

NickB2005

> @unclejohn said:
> http://homeguides.sfgate.com/replace-shower-mixer-valve-102141.html
>
> Ask who ever installed the shower fixture if it's this type.

Yeah, it was. I remember before they boarded everything back up.

This is a picture of it now, basically where the shower handle is for the temp I need to turn it all the way around and get it to this position it’s in to get it warm, not hot.

unclejohn

You should be able to get to the back of that and adjust it for hotter output.

EBEBRATT-Ed

And yes, I live in MA as well. The city water is a lot colder than normal due to the recent cold snap.
It can throw things out of wack

rick in Alaska

If you are getting hot water at the sink, but not the shower, then most likely the shower valve is the problem. Depending on the valve, it might have a thermostatic element in it that is sticky.
Personally, I would get your plumber back over there.
Rick

NickB2005

> @rick in Alaska said:
> If you are getting hot water at the sink, but not the shower, then most likely the shower valve is the problem. Depending on the valve, it might have a thermostatic element in it that is sticky.
> Personally, I would get your plumber back over there.
> Rick

Thank you. I should say I am getting hot water I just have to spin the handle all the way around but it’s definitely not as hot as it was 2 months ago and I never had to spin the handle that far. My plumber was going to replace the mixing valve on the hot water tank, but I don’t think that’s it.

JUGHNE

The shower valve may have a mechanical stop/limit for the hot position. It may not be set to the hottest position.
Look for instruction papers.

hot_rod

Use Ricks advice and see if the other HW faucets in your home supply hotter water. if so it may be the shower valve. if the temperature is too low at all your faucets, I'd look at the mix valve.

Depending on which model they used, some are not adjustable above 120F. that should be plenty.

Is there a recirculation pump and piping? That can confuse mixing valves unless properly piped.

NickB2005

> @hot rod said:
> Use Ricks advice and see if the other HW faucets in your home supply hotter water. if so it may be the shower valve. if the temperature is too low at all your faucets, I'd look at the mix valve.
>
> Depending on which model they used, some are not adjustable above 120F. that should be plenty.
>
> Is there a recirculation pump and piping? That can confuse mixing valves unless properly piped.

There is a recirculating pump and piping I’ve attached a picture. Honestly, I’ve had this installed nov 2016 and haven’t had any issues up until 2 months ago and never really thought of it as an issue more of an annoyance but didn’t think twice about it.

hot_rod

Bob used to hang out here he does fine work.

If the problem just started I'd suspect the mix valve needs to be disassembled and cleaned, de-limed. Thermostatic mix valves do need routine service, depending on water hardness in some areas valves need a yearly cleaning.

I'd ask about the caps on the Spirovent also

NickB2005

So the inspector came to just sign off on the construction in my basement. Added a shower and re did the sink and toilet and basically remodeled whole thing. Plumbing inspector said the hot water is only at 105 and he can’t pass us but what he said to do was because I already had a valve on the front of the boiler was to get rid of the mixing valve and pipe that opening closed. He said no need for the mixing valve if the other valve controls what the boiler is supposed to do for hot water. Thoughts? The current plumber on the remodel said he could repipe it in 30 mins or so, but is that the right thing to do? Remove that Honeywell mixing valve?

EBEBRATT-Ed

I would keep the mixing valve

NickB2005

> @EBEBRATT-Ed said:
> I would keep the mixing valve

Even with the other valve on the front? To get pass the inspection they are going to take it off and re pipe it. However, the guy who installed it wants to take a look at the valve and pipe when he gets back to see what went wrong with it.

unclejohn

Maybe I missed a post but can you just turn up the mixing valve and or the tank temp? I would also keep the MV.

NickB2005

> @unclejohn said:
> Maybe I missed a post but can you just turn up the mixing valve and or the tank temp? I would also keep the MV.

Turned up the mixing valve as high as it goes.

I didn’t think to turn up the boiler.

Alan Welch

Not sure what other valve inspector was talking about. The temperature of the water in the tank should be controlled by the gray Honeywell control on the side of the tank. What is that set to?

NickB2005

> @Alan Welch said:
> Not sure what other valve inspector was talking about. The temperature of the water in the tank should be controlled by the gray Honeywell control on the side of the tank. What is that set to?

Turned it all the way up to 140 but the thermostatic valve on the front is set to 130 and that’s what the boiler is putting out for demand for the hot water tank.

Alan Welch

I think the first response to the original post covers it, you lose temperature at the mixing valve, and if the boiler is circulating 130 degree water to the indirect tank you will never get 140 degree water to mix down.

NickB2005

So, the plumber doing the plumbing on the remodel removed the mixing valve today and 5 mins after water temp was back between 120-130. 5 hours later still at 120-130. I don’t know what but something must’ve happened to the mixing valve but he left it with me and I’ll have bob who installed it take a look.