Issues with Honeywell AMX3 series mixing valve

ejn

I have a newly installed State ProLine water heater with a Honeywell AMX3 series mixing valve on it to boost my effective hot water capacity. However, the hottest water I get at the tap is 105 F, even though I've cranked my water heater to 150F and the valve all the way open. Has anyone dealt with similar issues? Is there something I'm missing? Is there a certain protocol to cranking up the heat?






BTW I am not a plumber, just a homeowner trying to sort out my own problems. Thanks in advance for any help.

Zman

Have you tried turning the valve the other way?

ejn

Zman said:

Have you tried turning the valve the other way?

Yes, just tried it again. All the way hot, all the way cold, somewhere in the middle. Never got higher than 105.

BillyO

You loosened the center screw and let handle pop out then turned?

hot_rod

Most mixers have a limiting stop under the cap, make sure it is not throttled down.

Did you confirm the tank is actually putting 150 to the H port.

Thermostatic valves want a 25-27° difference between hot in and mixed out to regulate accurately.

They also need at least a .5 gpm flow get enough resolution across the thermostatic "pill" inside to accurately regulate.

Is there a recirc pump on the system?

ejn

BillyO said:

You loosened the center screw and let handle pop out then turned?

I think that's for a different model? This one says "Push in to turn". You can see it in the first photo. Unless I'm mistaken about how to turn it up?

This is the AMX300 Series DirectConnect mixing valve. It seems like the one where you have to loosen the screw is the Honeywell/Sparco AM100 series.

hot_rod said:

Most mixers have a limiting stop under the cap, make sure it is not throttled down.

Did you confirm the tank is actually putting 150 to the H port.

Thermostatic valves want a 25-27° difference between hot in and mixed out to regulate accurately.

They also need at least a .5 gpm flow get enough resolution across the thermostatic "pill" inside to accurately regulate.

Is there a recirc pump on the system?

I don't think I have a recirc pump on my system.

I don't have the thermo-strip thing to confirm that the water heater is actually putting out 150 to the H port, but it sure feels hot to the touch under the insulation, and the H nipple below the valve. Is there a good way to check the temperature without a thermo strip thing?

I apologize if I'm asking real basic questions. This is my first time doing this stuff.

hot_rod

ejn said:

BillyO said:

You loosened the center screw and let handle pop out then turned?

I think that's for a different model? This one says "Push in to turn". You can see it in the first photo. Unless I'm mistaken about how to turn it up?

This is the AMX300 Series DirectConnect mixing valve. It seems like the one where you have to loosen the screw is the Honeywell/Sparco AM100 series.

hot_rod said:

Most mixers have a limiting stop under the cap, make sure it is not throttled down.

Did you confirm the tank is actually putting 150 to the H port.

Thermostatic valves want a 25-27° difference between hot in and mixed out to regulate accurately.

They also need at least a .5 gpm flow get enough resolution across the thermostatic "pill" inside to accurately regulate.

Is there a recirc pump on the system?

I don't think I have a recirc pump on my system.

I don't have the thermo-strip thing to confirm that the water heater is actually putting out 150 to the H port, but it sure feels hot to the touch under the insulation, and the H nipple below the valve. Is there a good way to check the temperature without a thermo strip thing?

I apologize if I'm asking real basic questions. This is my first time doing this stuff.

150F is really hot, I doubt you could put a hand on it for more than a second?

An oven thermometer may read low enough, strap it against the hot pipe at the tank , wrap a rag around it to insulate.

ejn

150F is really hot, I doubt you could put a hand on it for more than a second?

An oven thermometer may read low enough, strap it against the hot pipe at the tank , wrap a rag around it to insulate.

All I got is a meat thermometer. If I touch the tip of it to tank underneath the insulation it gets to around 140F, and that's just the tip of the meat thermometer touching the side of the tank, so I don't think the water heater unit itself is the issue.

GW

Ouch! One full second at 150 would get ya good

GroundUp

All the other Honeywell mixers I've used (although not the one you have in particular) require the center screw to be threaded out and the knob pulled out away from the valve body in order to adjust. Then once the desired temp is reached, the knob pushed back in, and the screw is replaced, the knob cannot be turned by bumping it or children messing around or whatever. Others, like Webstone, sometimes you have to physically remove the knob and re-index it on the valve stem to further adjust. Perhaps that's the case here?

HVACNUT

Call Honeywell customer support tomorrow. Have numbers ready and dont tell them you're using a meat thermometer for crying out loud. Say your using a K1 clamp on thermocouple.

I've never used that model but it looks like it cant be piped incorrectly if you wanted to.

Did it come with their little strip thermometer that affixes to the mix pipe?

I use a 3/4 x 1/2F x 3/4 brass tee with a well thermometer.

hot_rod

Valves do get assembled wrong at factories occasionally, maybe it has 1070 guts in it. 1070 valves are limited to 120F output.

Did you read the directions about adjusting then limit stop? That too could have been mis adjusted at the manufacturing process.

ejn

These are the directions I have been going off:
https://forwardthinking.honeywellhome.com/related_links/water/amx_300/install/62_3113.pdf

I didn't install the valve, just trying to adjust it.

hot_rod

ejn said:

These are the directions I have been going off:
https://forwardthinking.honeywellhome.com/related_links/water/amx_300/install/62_3113.pdf

I didn't install the valve, just trying to adjust it.

What faucet are you running to test the outlet temperature? The instructions mention 1- 1.5 gpm minimum flow. Lav and kitchen sink run .35- .5 gpm on newer models, shower heads should flow 1- 1.5 gpm.

Point being you might not get an accurate mix on low flow faucets. Run a few faucets and maybe the shower at once and see if that changes anything. Worth a try.

Dave H_2

@ejn
I guess the bigger questions are;
Has this ever worked? How long ago was this set-up?

I ask only because I experienced an issue myself about a year ago. The town was doing maintenance on the system and ended up getting alot of sand in the pipes and my mix valve had the screens all clogged up. And the valve was only installed less than three months earlier

Dave H.

ejn

Dave H_2 said:

@ejn
I guess the bigger questions are;
Has this ever worked? How long ago was this set-up?

I ask only because I experienced an issue myself about a year ago. The town was doing maintenance on the system and ended up getting alot of sand in the pipes and my mix valve had the screens all clogged up. And the valve was only installed less than three months earlier

Dave H.

It's only been set up a few weeks. There may be debris in there, not sure yet.

hot_rod

I would certainly check the screens to assure they are clear. Plugged screens usually affect the flowrate more than the mixing function. Do you get any temperature change as you rotate the handle? If so the cartridge snd spool are free inside, it seems like the stroke or travel on the thermostatic "motor" inside is limited. or the thermostatic cartridge is faulty.

I'd think the installer would first check these simple things or swap out the valve to see if that corrects it?