New installation of Resideo Braukmann AM-1 Mixing Valve rattles

toofastdad

I just had a new Natural Gas combi boiler installed and the DHW mixing valve makes a lot of noise. The heating company came by and removed the check valve on the hot water side but it is still making a lot of noise. Does anyone have a solution to this issue?

Thanks

Intplm.

Noise?
Something might be caught in the piping that is rattling around in there. Was it installed by soldering the joints? is a small bit of solder caught in there?

You say the check valve? There are, if memory serves," two" check valves in those units. Did he take both out and then put them back?

I would double check that and also flush the system of debris.

hot_rod

Unless you have a recirc, you don’t need the checks. Its about the only part that moves and could make noise.
 Checks are required on the ASSE 1017 valve, a point of use valve. Sone valves have dual listing 1017 and 1070, so they include checks.

toofastdad

@Intplm. He just took out the hot water side and it still rattles.

toofastdad

@hot_rod Here’s a photo of the valve and boiler. I don’t think there’s a circulator but I’m just a home owner and not a professional installer so I don’t really know but I think it’s a closed system and is just connected to the main cold water system. The boiler is a NTI TRX 199C https://ntiboilers.com/product/trx

dko

More straight pipe before the hot and cold inlets will help immensely. It is definitely the check valve making the noise, as the noise will be gone if you remove the check from the cold as well.

Common issue brought up with the AM-1 mixing valves and other similar valves with the spring checks mounted directly on the body instead of farther out on the tailpiece.

What is your water pressure? If high, reducing pressure will help as well.

toofastdad

@dko The water pressure is city water which is pretty stable and not too high, it’s more on the low side.

toofastdad

@hot_rod The valve that is on the system is a resideo Braukmann AM-1 Series ASSE 1017. Are you saying that I don't need the check valves?

Thanks, Colin

hot_rod

The valve is in a heating application by the looks of it? You do not need either check in that application 

toofastdad

@hot_rod It's for the domestic hot water. We get the noise when you turn on the hot water tap.

hot_rod

The checks are not required in a 1017 mix valve, they are in a 1070. I think you would be fine to remove them both. One purpose is to prevent hot or cold from pushing into the opposite side. If the hot pressure was higher than cold for some reason it could push into the cold line.

If you have a recirc pump on the DHW, you want a check. But it doesn’t need to be in the thermostatic valve necessarily. Do you have a thermal expansion tank on the system?

HomerJSmith

The AM-1 has plastic check valves and I doubt that the valves are fluttering and the source of the noise. You can remove the knob and then remove the thermostatic valve element and inspect everything. The AM-1 comes with a stick-on temperature strip which should be stuck on to the mixed outlet pipe of the valve. You can then set the valve to the correct outlet temp. This would allow you to loosen the screw holding the knob to the valve stem, pull the knob back and rotate the knob to its full travel and then set it to the desired outlet temp. That might give you more information. I assume the pressures on the hot and cold sides of the valve are equal.
I always ask the customer what the complaint is, but never take their word for it. As one President said, "Trust but verify." When it comes to noise, I have an inexpensive mechanic's stethoscope you can get at an auto parts store or Harbor Freight that I use to pinpoint the source of the noise. You might try that.
In all my experience, I have never had a noisy AM-1 valve. I would be interested in the cause of your problem and your solution to it.

SeanBeans

@hot_rod can you pipe a recirc in on an NTI combi?

hot_rod

The manual shows  some dhw options
It does  recommend a check on the mix valve outlet, and a balance valve