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Aquahot loosing Boiler fluid

December 03, 2022, 10:01:55 pm

Had my Boiler fluid changed a few months back. Ever since then I have been steadily loosing Boiler fluid. Not seeing it anywhere on the concrete in garage
 Took it back to the aquahot repair place. They spent a while looking for the leak. Registers. Aquahot. Reservoir. No leak found. Still loosing it. Never lost any prior to changing Boiler fluid? Air in system? I  about done with my second gallon in filling it. Stumped

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Re: Aquahot loosing Boiler fluid

Reply #1 – December 03, 2022, 10:30:46 pm

Did it get burped after changing out fluid?

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Re: Aquahot loosing Boiler fluid

Reply #2 – December 04, 2022, 12:49:43 am

Why did you have it changed?  Rare to need to change fluid in the Aqua Hot tank unless you contaminate the fluid.

What was used as the replacement fluid?  The 1998 Aqua Hot uses engine antifreeze, not GRAS Boiler Fluid unless the Aqua Hot has been replaced with a new one or a remanned one.  Then Boiler Fluid would be needed.

No mater which type of fluid is needed, it all turns dark over time.  But does not need replacing usless you contaminate the fluid or wish to spend the money to do so.

Now having changed the fluid for you, it may take a while to get air pockets out of the heating zone loops.  As that air makes its way back to the coolant tank, more new fluid will be needed.  Once all the air is purged, adding fluid will stop.  If you really had a leak, a little fluid, boiler or engine antifreeze, goes a long way and you would see the leak some where sooner than later.

Permit me to help you spend your money by replacing the coolant with Century brand boiler fluid sourced from Aqua Hot Heating Systems for only $91.99 per gallon.  We will need 17 gallons to have a little extra, all for only $1563.83, plus tax. plus labor.

That fluid can be purchased else where for about $39 a gallon.  If using engine antifreeze, you only need 8 gallons plus 9 gallons of distilled water.  But you need an older Aqua Hot with fuses and clear relays and a stainless steel case, no electronic control board to use engine anti freeze.

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Re: Aquahot loosing Boiler fluid

Reply #3 – December 04, 2022, 08:52:34 am

Rudy, so Century brand boiler fluid is what I need to top off my reservoir on 2013 model.  When cold it is a little below the cold mark.

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Re: Aquahot loosing Boiler fluid

Reply #4 – December 04, 2022, 11:13:09 am

You need GRAS boiler fluid, Generally Recognized As Safe.  Century is sold in green and red colors and is pre-dulited ready to use.

Camco and Starbright red colored fluild gallons are sold as concentrate.  They need to be diluted 50/50 with distilled water.

It is recommended to not mix the colors but I have not had anyone tell me why a colorant is not compatible with another coorant.

Your hot freshwater copper coil is in the coolant tank.  So a split in the coil would open the hot water to the coolant.  But only if the coil splits usually due to freezing.

The older heaters have the hot freshwater coil wrapped around the outside of the coolant tank emersed in heat transfer mastic.  No coolant contamination of the hot freshwater is possible.

So use the boiler fluid of your choice, just no engine antifreeze.

AND, for topping off of the overflow tank, just plain Distilled Water is fine.

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