Honeywell mixing valve not consistent

spacoli

Hi to all. I have a small radiant floor loop set up and the mixing valve is modulating as the boiler  temp modulates. I know there might be a degree or two here and there, but this is temp is moving consistently with the boiler temp. I woke up this morning to a cold spell and my temps where way too high. Bad mixing valve? Thanks

Weezbo

spacoli ,

that is a proportional valve .

which basically means it has aa set temp , yet it is somewhat dependent upon the temp it sees. on the hot side.

so during a rapid change of temp outside the heat source may ramp to meet where it thinks the water temps need to be , that could possibly move the gauge upwards of ten degrees or maybe even more.



so it may be fine .

there is one that i like that goes to 100 degree yet it can bounce above that .

it is a Sparco Honeywell AM series 60 -> 100 degree ,



hope you stay warm this winter , the next couple months are not likely to be getting warmer where i live.



hope that helps .

*~//: )

spacoli

Honeywell AM101R-US-1 Mixing Valve, 70-180F Heat Only

This is the Mixing valve. Thanks for your reply.

hot_rod

try cleaning the spool

they sometimes get junk inside that prevents that balancing spool from moving up and down freely. Rare that the actual thermostatic "pill" fails, it usually the spool.



Take a replacement valve, swap it out the, and bring the old one back to your shop for a cleaning and inspection. Look for bad o-rings, nicks, flat spots, tears, etc.



Also check the inside bore of the valve, it needs to be clean and smooth for the spool to slide freely. Some brands have a chrome plating inside and if it wears away the spool may not move freely.



Simple valve inside, keep track of the spring and pieces when you disassemble it.

Snowmelt

Picture

If that's the picture there is a chance it's installed wrong, do you have a better picture?

spacoli

Installed wrong?

What do you mean installed wrong? What are you looking for or at before I take a picture?

RobG

Mixing Valve

Spacoli, I just re-read your post and it sounds like you have a modulating condensing boiler? If so, you have no need for a mixing valve, you can use outdoor air reset or set the limit to your supply temp. Is this the case?



Rob

spacoli

Yes, but

The rest of the house is baseboard and mostly cast iron rads. This is an addition from the main heat loop that needs to be a lower temp. Thanks