Community Forums

Alpinexplore · 03-21-2019, 12:04 PM

I have a 2001 Monaco Dynasty with a 3-zone Aquahot furnace heating system. Recently, the living/room kitchen zone quit heating. The first thought that comes to mind is that the pump for this zone quit working as the bedroom/bathroom zone still heat correctly. Does anyone know if there might be other possible causes to check before assuming a problem with a pump? The thermostat still works correctly for air conditioning and fan so it appears the problem is not with the thermostat.

Thank you, ... Christopher

RamiDav · 03-21-2019, 12:34 PM

The most common issue for your problem is a sticking check valve .
There is one for each pump or zone . It will be near the pump .
You can usually tell by feeling the pipes , when the check valve is opening properly
the pipe will be hot on both sides of the ck valve when sticking it'll be cold on one
side .
You can usually get it unstuck by rapping it sharply with a screw drivers handle .
Oh the pump should be running .

Ray

Monaco Wolfy · 03-21-2019, 01:04 PM

x2 on a possible sticky valve and feeling for heat on the pex pipe. On my 04 Windsor the valves are located just above each pump. Yes, as you know, the pump must be running for that zone to heat. If the pump isn't running, check to see if it has current to it. If not, trace it back to the control panel and check the connection there.

Outbound · 03-21-2019, 02:47 PM

Ditto on sticky valves, RamiDav is right on, should be able to feel pipes to tell if valve is open.

K7JV · 03-21-2019, 09:33 PM

Actually, I think you already know that the circuit is probably not circulating to the heat exchangers. If your kitchen fan is running and the air is cool, with all you said about your other zones, everything is working except the circulation system on that zone 1. Do check and make sure that you don't have warm air coming from your front register under the dash console! If you do have warm air there, the problem is with the fan control and/or power to the kitchen heat exchanger. If the front exchanger is also emitting cold air, like Ray, Wolfy and Outbound suggested, it is either the pump or the check valve.

Our '06 Dynasty has the AHE-100 system. If yours is like ours, there are six hoses coming out the top of the unit. The three on the left are the outgoing lines and the three on the right are the return lines. The front pair serve the bedroom. The middle pair serve the bathroom and the basement. The back pair serve the kitchen and living room. If you can rap on that back left line, hopefully on the check valve itself which likely extends out of the top of the unit, you can see if that gets it back to working. If it does, you've found the problem. (Please know that you have not "fixed" it, you've just identified it. It may stick again and ultimately need to be replaced.)

If that doesn't restore operation, check to see if +12V is available on the bottom two terminals on the long terminal strip on the right side of the control board. That should be connector JP3, and the bottom two should be terminals #1 and #2. They should be labeled PUMP3- and PUMP3+. The conductors should be red on the bottom terminal and black on the next terminal. If your thermostat is calling for heat on the furnace setting, and you don't have +12 volts on that terminal pair, I would believe that the control board is likely to be the problem. If that were the case, I would make all efforts to make sure of that outcome before I sought a new board. For example if your unit is not the AHE-100, your configuration might be different. You should be able to download a maintenance manual for your unit from AquaHot.

If you do find that +12 volts is present on those two terminals, you will need to pull the cover and see if the pump is running. I think it will be the lowest of the three that are mounted in a row. The fourth one is for the engine loop. If it is not running, I would try to read the voltage on the two wires that connect to that pump, if you can get at them. If you have +12 volts there and the pump is still not running, then the pump is most likely the problem.

If the pump is running and you still have cold air from the kitchen and living room units, then it most likely is the check valve and rapping on it was not sufficient to free it up from sticking.

These suggestions are in order of difficulty in doing them. I wish you the best of success in troubleshooting your unit. Let us know how you do.

K7JV · 03-24-2019, 05:42 PM

Any updates? Successes?

Outbound · 03-24-2019, 08:01 PM

No word from OP?

Woodman018 · 03-24-2019, 09:29 PM

One other possible problem could be the relay for that pump has gone bad. The relays are inside the case of the aqua hot and are about 1 1/4 inch square by 2 inches long with a small bent keeper wire on them to hold them in place. You can simply swap them to see if that makes a difference and if it does just replace the bad one. Guess how I know this.
Dave