Aqua Hot issues

[pwhittle]

My 94 Signature has an Aqua Hot model # 421/12 with a couple peculiarities.

There are three thermostats in the coach plus one in the basement.:

Living room thermostat controls two registers under couch plus one in the kitchen.

The bedroom thermostat controls one register in the bedroom and another in the bathroom.

The third thermostat is in the toilet room and controls a single register in the toilet room.

Sometimes the thermostat in the bedroom clicks but the fans in the registers do not come on.

The thermostat in the toilet is only powered when the bedroom thermostat is on and set to above the temperature)and trying to power the registers, whether or not the bedroom/bathroom registers are running or not.

The wires going to the bedroom thermostat are light weight wires like are connected to the connector inside the Aqua Hot.

The wires going to the toilet thermostat are thicker gauge wires like run to the registers.

There is also a basement thermostat with a temperature probe in the tank storage area. Today the fan was not coming on regardless of where I set the thermostat, but when it is colder, I have heard it come on.

The zone pump that was on in the Aqua Hot today was varying in speeds like a poor connection.

Are these known issue or are we back to basics like replacing the relays and cracking the grounds?

Paul

[Mike Canter]

Paul that is a fairly common configuration and your thermostats are like mine. When I select furnace on a zone it turns on a circulating pump for that zone then when the temp setting calls for heat it turns the baseboard register fan on. So if you turned all your thermostats to furnace and all the temps to 85* then all the fans should come on. I have two registers in the bathroom and one of the fans can be turned off or on by a separate switch. The fans are all 12 volt and I doubt that every fan has a bad ground or relay so if the fans are varying in speed then either your batteries are weak or you have something else turning on or off that is loading down the battery. As far as the fan in the basement the only time I can the fan to come on so I can hear it is if the ambient temp is below 55*.

[pwhittle]

Spent some time reading the manuals and checking things out.

There are 3 zones plus one sub-zone, plus the engine pre-heat. Mine is a 1994 and has separate thermostats for each zone as well as separate controls for the A/C's

Zone 1: Living area with two registers under the couch and one in the kitchen controlled by the thermostat in kitchen.

Zone 2: Bedroom/Bathroom with one register in bedroom and one register in bathroom controlled by the thermostat in bedroom.

Subzone 2A: The register in the toilet is controlled by a thermostat in the toilet, but the register is fed hot water when the bedroom/bathroom thermostat is on.

Zone 3: Basement heat controlled by thermostat in the basement.

The engine pre-heat is controlled by a switch by the driver.

The original problem of the bedroom/bathroom thermostat not working all the time and the varying pitch of the pump for that zone was tracked down to some loose screws on the relay blocks on the outputs to the pump and fans. Some of them were out a turn. Snugged everything down, and it is working as expected!

All is well again in Aqua Hot land.

Paul

P.S. My model is a 431/12. I typo'd the wrong model in the orignal post.

[RonNBama]

Happy to hear that you won the battle. I had a peculiar issue where the rear two zones (bathroom and bedroom) would not produce heat unless both were turned on. I put a temporary fix in place (jumpered the relays). That was five years ago. Now I am experiencing the same symptoms of variable-speed fans in the living room zone. All relay screws are tight but a "wiggle" on the relay will produce the speed variations. Swapping relays does not change the symptoms so I assume I must have a bad base. Never had a base fail.