Indirect water tank temperature issues

kalex1114

Hello all. I replaced my boiler/water heater about 2 years ago with Lochinvar KBN 110 and Bradford white PowerStor SW-2-65-L idirect water tank
I also had the plumber install Honeywell AM-1 mixing valve on the tank.
For the most part everything works great but sometimes my hot water is luke warm. Doesn't happen often and i noticed mainly it happens when there is a large water usage
Most recent it happened was yesterday. Went to sleep and water was warm at full hot open and after I woke up, its fine. Another few times it happened
when wife wanted to use the soaking tub. my WAF tanked those 3 times

I have my mixing valve set at 120 and water temp in the tank is 140. I have my lochinvar set to 4 degree so it kicks on when its 135.
Temp sensor on the indirect is located towards the bottom of the tank. Temp sensor seems to work fine.
I did notice that mixing valve siezed on me. I tried to adjust it and its not turning. Any ideas on whats happening and how to fix it?
I'm guessing mixing valve got something inside it stuck and its not mixing water correctly?
not sure what else to check. I called the plumber and he told me to just get another mixing valve and replace it. but I want to make sure i do it right and
don't have to do this again.

Any recommenadation on a mixing valve to get?

here is an album to the pictures:

https://photos.app.goo.gl/B4YjLktjwofjd4dR9

kcopp

The mix valve sometimes needs to get "woken up". That involves turning the knob up and down a few times. I would be willing to bet that the knob has been locked in place w/ the set screw. Loosen it up and pull up. It should turn freely.

kalex1114

kcopp said:

The mix valve sometimes needs to get "woken up". That involves turning the knob up and down a few times. I would be willing to bet that the knob has been locked in place w/ the set screw. Loosen it up and pull up. It should turn freely.

i did remove the set screw. no movement on the knob. its stuck

kalex1114

Yep just confirmed it. took the screw out. pulled the knob out a bit to engage it and tried to turn the knob. no movement at all

Larry Weingarten

Hi, Can you post a photo of the valve? It might be possible to remove the top of the valve and then get to and descale the innards.

Yours, Larry

kcopp

In that case...from the pictures you sent a link to I would just swap it out for another Honeywell. Unfortunately that is the only valve that will fit in there w/o doing some re-piping. You could try to disassemble and clean as Larry suggests if you have the time and want to give it a go...

JohnNY

That mixing valve maxes out at 120°. I find that mixing valves don't work well at either extreme end of their settings except at prolonged draw. You've also got no heat trap installed.

kalex1114

JohnNY said:

That mixing valve maxes out at 120°. I find that mixing valves don't work well at either extreme end of their settings except at prolonged draw. You've also got no heat trap installed.

which mixing valve would you recommend?

kalex1114

Larry Weingarten said:

Hi, Can you post a photo of the valve? It might be possible to remove the top of the valve and then get to and descale the innards.



Yours, Larry

Here is the picture:

HVACNUT

How many gallons is the soaker tub? If the mixing valve is operating properly, I would raise the tank temp to 160°.
If the mixing valve is faulty, then swap out with the same. It's a good valve.
If it were mine, I'd keep the tank at 160° regardless.
The tape thermometer is NG, and the bulb one is probably too not accurate where it is. Get a good 3/4" surface mount clamp thermometer.

hot_rod

In hard water conditions, which it looks like you have based on the valve to the right, you may need to descale them yearly or maybe even every 6 months

Consider a spare so you can rotate in a cleaned one when it seizes.

Probably the highest maintenance valve out there, thermostatic mixers.

kalex1114

> @hot_rod said:
> In hard water conditions, which it looks like you have based on the valve to the right, you may need to descale them yearly or maybe even every 6 months
>
> Consider a spare so you can rotate in a cleaned one when it seizes.
>
> Probably the highest maintenance valve out there, thermostatic mixers.

I have a whole house water softener installed not sure why water is hard. Shouldn’t be

@hvacnut - I can keep the tank at 160? It won’t damage the tank being so hot?

How hard is it to rotate them?

Larry Weingarten

Hi, Sorry I missed the link to your images... was on my phone. I think my question has been answered, in that the guts of the valve are clearly accessible and likely easily replaced. Keeping a spare on hand sounds like it will eliminate most of the downtime when the valve misbehaves.

Yours, Larry

JohnNY

kalex1114 said:

JohnNY said:

That mixing valve maxes out at 120°. I find that mixing valves don't work well at either extreme end of their settings except at prolonged draw. You've also got no heat trap installed.

which mixing valve would you recommend?

https://www.supplyhouse.com/Honeywell-Sparco-AM101-USTG-1LF-3-4-Lead-Free-Union-Sweat-Mixing-Valve-w-Temperature-Gauge-70-145F

kalex1114

> @JohnNY said:
> (Quote)
> https://www.supplyhouse.com/Honeywell-Sparco-AM101-USTG-1LF-3-4-Lead-Free-Union-Sweat-Mixing-Valve-w-Temperature-Gauge-70-145F

Thank you. Is this same model? Honeywell AM101-US-1 Sparco Thermostatic Mixing Valve, 3/4" Union-Sweat 100-145F https://www.amazon.com/dp/B002DGEOJC/ref=cm_sw_r_cp_api_i_STfRDb06RJCXN

JohnNY

Looks like it. Yes.

kalex1114

JohnNY said:

Looks like it. Yes.

Thank you.
do I need to drain the indirect to swap it? or just close of supply valves and open a faucet to relieve pressure and swap it?

Intplm.

@kalex1114 Or maybe change to something like this

kalex1114

Intplm. said:

@kalex1114 Or maybe change to something like this

may ask why change?