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AquaHot antifreeze usage

December 12, 2012, 02:26:00 pm

I have been running my bay heat, along with the 3 interior coach heaters on electric.  Can someone tell me what the average consumption of the antifreeze solution would be?  I discovered the tank below the cold level line but not quite empty, thankfully.  Topped it up, and in 3 days it has gone down to an inch below the hot line, so obviously it is consuming fluid, no leaks noticed. 
Mike

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Re: AquaHot antifreeze usage

Reply #1 – December 12, 2012, 05:44:19 pm

Hi Mike,

The level in your over flow tank will fluctuate based on the AquaHot liquid temp. Before determining if there is a leak, shut down all the zones, bring the unit up to full temperature with the diesel burner and then check the tank. I would top it off if necessary. Do the the same in a couple of days. If the level has changed one area to check is the over flow hose connection at the unit. That hose can be problematic. Mine failed less than a year after replacing the AquaHot unit.  I replaced mine with McMaster-Carr P/N 51075K33

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Re: AquaHot antifreeze usage

Reply #2 – December 12, 2012, 07:07:34 pm

Hi Mike,

As Bob said, the over flow hose is the most likely culprit followed by the radiator cap.

Remove the over flow tube at the heater neck, cut an inch or two off and reconnect.  The tube gets brittle due to the heat  A constant tension hose clamp should be at each end of the over flow tube as the connection needs to be air tight.

While replacing the radiator cap with a 13 lb one from almost any auto parts store (I like the kind with the pressure relief lever), top the heater tank coolant all the way up to the radiator cap neck.  Let heater cool so you do not toast your finger tips.

Run the diesel burner up to temp and when it cycles off, top the over flow tank to near the hot line.

Other places to check are, sometimes the fan coils in the coach will seep coolant, the pan under the burner should be coolant free so a quick check here will reveal a leak some where in the plumbing of the heater.  Other than checking the pan under the burner for coolant stains, I would not try to access the fan coils till I verified the tube and cap fix did not solve your concern.

Hope this helps you.

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Re: AquaHot antifreeze usage

Reply #3 – December 12, 2012, 07:58:36 pm

Check around where the exhaust exits under the coach. I had a coolant leak there that unfortunately was a leaking coolant tank. There was no coolant visible in the pan.

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