Paloma PH-24M-DN TANKLESS WATER HEATER ISSUE

[spf8298]

I have two Paloma PH-24M-DN water heaters that are plumbed on a common copper water line. They feed my 3 self serve bays and 1 IBA. One of the heaters seems to run any time it's called upon for hot water, but the other doesn't. The pilot lights are functioning on both units. Does anyone have any suggestions on a remedy or trouble shoot before I call the plumber? I would think that any time hot water is called for, they would both fire up and heat water in unison.....any help would be appreciated.

 

[MEP001]

The most common issue with these is the diaphragm that leaks where the valve can't open with flow. Pull it apart, and if there's any water on the wrong side, replace the diaphragm.

 

[spf8298]

The most common issue with these is the diaphragm that leaks where the valve can't open with flow. Pull it apart, and if there's any water on the wrong side, replace the diaphragm.

Paloma has a rebuild kit that include the diaphragm, Screws, o-rings etc for $82 shipped. Seems pricey when I can get the diaphragm for $25 from kleenrite or dultmeier. Is it necessary to change replace all those parts, or should just replacing the diaphragm fix me up?

 

[cwguy.com]

I am not a Paloma expert (I never installed mine) but do your heaters use a controller? If they are run in series some need a controller to work correctly and I believe they alternate turning on. Maybe the controller is messed up?

 

[MEP001]

I've replaced just the diaphragm many times, wouldn't hurt to keep a full kit on hand since the screws can corrode and the o-ring will eventually get brittle or swell.

The Paloma in question here has no controller or even electric supply, it's all mechanical with a standing pilot.

 

[spf8298]

I've replaced just the diaphragm many times, wouldn't hurt to keep a full kit on hand since the screws can corrode and the o-ring will eventually get brittle or swell.

The Paloma in question here has no controller or even electric supply, it's all mechanical with a standing pilot.

You are correct on your comment. My Paloma's are all mechanical and are original equipment, so that puts them at 27 years. I think I'll just take the hit and order the whole kit this time. I'll keep you posted on the results when I'm done.

 

[spf8298]

You are correct on your comment. My Paloma's are all mechanical and are original equipment, so that puts them at 27 years. I think I'll just take the hit and order the whole kit this time. I'll keep you posted on the results when I'm done.

I got the diaphragm on my non functioning Paloma replaced and it will ignite now, however, it's still seems to not be working correctly. It takes all three of my self serve bays running in order for the pressure to drop enough for the second heater to kick on. With it being plumbed right in line with the first Paloma I would think they would both turn on at the same time any time there is demand for hot water. I did recently install generant water pressure regulators on each of my self serve pumps to regulate the city water pressure because I was having trouble with soap delivery. Could those regulators affect the water pressure enough that it would affect the functioning of my hot water heaters?

 

[MEP001]

It might help you to know that it's not based on pressure drop, it's based on flow. You're probably not getting enough flow through the second heater for it to come on. It shouldn't be a problem unless there's enough getting through without it igniting to keep the water from getting hot.

 

[spf8298]

It might help you to know that it's not based on pressure drop, it's based on flow. You're probably not getting enough flow through the second heater for it to come on. It shouldn't be a problem unless there's enough getting through without it igniting to keep the water from getting hot.

Would switching my spray tips have caused the flow to decrease that much? We switched from 4008 tips to 1506 tips.....

 

[Davianson]

I have two Paloma PH-24M-DN water heaters that are plumbed on a common copper water line. They feed my 3 self serve bays and 1 IBA. One of the heaters seems to run any time it's called upon for hot water, but the other doesn't. The pilot lights are functioning on both units. Does anyone have any suggestions on a remedy or trouble shoot before I call the plumber? I would think that any time hot water is called for, they would both fire up and heat water in unison.....any help would be appreciated.

Hey do any of you have any of these old unusable diaphragms (intact with spindles) I could buy? Send pics please. Thanks!

 

[soapy]

Palomas come with a restrictor valve on the inlet side. I removed those valves on all of mine so they will flow a bit more water. My palomas were always plumbed in 1 per bay so I had a solenoid that opened for each one as that bay was called for.