[Richard]

Excellent, most fantastic summary. Thank you.

The following two statements are making me confused. The first is TSTAT 1 powers AH pump zone 3 which is front ship. AND Here in lies the problem you can only get AH pump zone 3 to come on by “jumping”.

Is it that you get a signal from the TSTAT 1 at the AH, but it doesn’t do anything?
Is it that the TSTAT turns on ah zone 3 pump, but not the cozy fans?
Or something else?

[Richard]

I am not trying to jerk you around. I am asking those specific questions because of unusual setup that AH uses which throws even an experienced electrical dude for a loop. Rudy said it, but let me emphasize it.

The tstat puts out a 12V positive signal. Aquahot uses a ground signal to turn the zone off and on. Simply feeding the tstat signal to the AH produces NOTHING. The way it works is the positive signal is fed to a standard Bosch style relay mounted on the AH. When the relay sees a positive signal it closes as you know. When it closes, it connects the 85 and 86 terminals to GROUND. This is bassackards from how relays are normally used to connect 85 and 86 to a Positive source. So, identify the black relay that has the tstat input from TSTAT 1. Is it getting a 12V positive signal on the input terminal ? If so, is it passing continuity from 85 to 86? And is that continuity grounded?

[Richard]

I have read this post several times. I think I answered some of my questions.

The Tstat for zone 1 does not activate either the pump or the cozy fans. If that is so, then your question of why doesn’t it work as it should is tied very closely to the relay that is wired to turn the 12Vdc positive signal into a ground signal .

The fact that jumping works says you do NOT have an AH problem, and please don’t rewire the AH until you have a chance to check out the black Bosch relay and determine if it is getting the signal, and then making the ground signal to the AH board.

I will try to take a picture of the relay, and post it in the morning. Dark and cold here now.

[rundlc]

Excellent, most fantastic summary. Thank you.

The following two statements are making me confused. The first is TSTAT 1 powers AH pump zone 3 which is front ship. AND Here in lies the problem you can only get AH pump zone 3 to come on by “jumping”.

Is it that you get a signal from the TSTAT 1 at the AH, but it doesn’t do anything?
Yes, this is the issue, the signal is there, but the signal does not turn on the AH pump 3 or the cozy fans



Is it that the TSTAT turns on ah zone 3 pump, but not the cozy fans?
Or something else?


The Tstat for zone 1 does not activate either the pump or the cozy fans. If that is so, then your question of why doesn’t it work as it should is tied very closely to the relay that is wired to turn the 12Vdc positive signal into a ground signal.

Keep in mind. The relay would be a relay that we add to bypass the issue of the tstat wire not triggering the cozy fans

[rundlc]

Richard, so there are relays already in the AH system somewhere? I didn't see any relays anywhere.

[Richard]

Ok, I probably have led you down a rabbit hole. I have learned that your setup is quite different than the one that I am familiar with. My sincerest apologies.

[rundlc]

Richard,

Do not even worry about the rabbit hole. I am truly a sponge trying to learn and understand.