Aqua Hot fluid growth update

[Cruzer]

Originally Posted by hawgguy

What is the proper nomenclature for the pump for the floor loop? The one located on the rear passenger side. Who makes it? Is it subject to failure. Mine is a little noisy (meaning I can hear it run) at times but seems to work well.

It's the booster pump.

Mine did go out and was replaced last week during my PDI. Actually, it's not just for the floor heat. I thought it was but had it explained to me by Chris, the Aqua-Hot tech at Entegra. The zone 1 heat front living area) and zone 2 heat in-floor heat) are connected in series so the juice runs through both of them. The thermostat merely shuts off the blower fans on zone 1 when not used. That's why you want to set the zone 2 thermostat significantly higher than zone 1. If I recall correctly PJ said something like 10 degrees more. If the booster pump fails, like mine did, you won't have hardly any heat coming out of the zone 12 heat exchangers. However, it will blow cold air because the boiler itself is hot and the thermostat is calling for heat. It doesn't know that the hot antifreeze isn't getting to the heat exchangers.

The booster pump is not one of those plagued Gorman-Rupp pumps used as the circulating and stir pumps that failed repeatedly. Different pumps have been used, including a Bosch pump. My booster pump began to make noise and eventually degraded from not quite getting hot to not getting hot at all. Chris replaced it with the same Buehler C20 pump now used in the circulating and stir pump positions. He stated that the C20 pumps have a higher flow rate and will work much better.

My system was all sludged up and is now flushed and refilled with pink Camco. Technically the green Century Transfer Fluid is approved by Aqua-Hot and dos meet the specifications. However, my personal opinion is that the green Century fluid is fine until something goes wrong. If you get a kinked line or failed pump it overheats and falls apart causing the sludge and a host of new problems. The system is a sealed system so sludge can only come from what is already there. That narrows it down to the Pex lines, pumps, connector hoses, boiler tank and the fluid itself. I feel that the red Camco stuff is more "fault tolerant" and doesn't break down if it gets hotter than it was designed to handle. Again, no proof of this. It is just my opinion but I feel pretty slid about this after what I've seen. The true test would be to heat some of each fluid up in a controlled environment and log some temperature and time readings. But now that I have the red Camco I don't see the need to bother with all that.

[brobox]

Good report Mark and thanks for letting us know what pumps that will work for the boost pump. It is amazing that AH stated the sludge was OK to run it the system, it won't hurt anything. However pumps running sludge continue to fail.
On the Sludge post someone did heat Century fluid on a stove and let it boil off with no sludge.

I know for a fact that the US Air Force would have grounded ANY plane with a spec of contamination until the system had a lab test run on the the cause of the contamination. Aqua Hot...."it's OK run it and we don't believe your lab test that shows high metal contamination".

[rogelling]

Mark, when I replaed the GRE pumps in the AQ with the Buehler pumps that were sent by AQ as part of recall, I did not replace the one that circulates the engine coolant, simply because it was a tough job and I have never used the engine preheat. So my question is, can I use that leftover Buehler pump to replace the booster pump? I want to flush out my system this fall and replace transfer fluid with Camco so it would be a good time to replace booster pump. My fluid has some sludge in it but it has not gotten any worse since I flushed out transfer fluid and replace with same.

[Cruzer]

Originally Posted by rogelling

Mark, when I replaed the GRE pumps in the AQ with the Buehler pumps that were sent by AQ as part of recall, I did not replace the one that circulates the engine coolant, simply because it was a tough job and I have never used the engine preheat. So my question is, can I use that leftover Buehler pump to replace the booster pump? I want to flush out my system this fall and replace transfer fluid with Camco so it would be a good time to replace booster pump. My fluid has some sludge in it but it has not gotten any worse since I flushed out transfer fluid and replace with same.

It's the same pump so yes, you can use it. The only consideration might be that you have the correct hoses connections. The Buehler C20 has a higher flow rate but as long as they are both the same hose size you'll be fine. I do recall that the GRE pumps were smaller and adaptor hoses were included in the kit but I didn't look that hard at the booster pump after it was replaced so can't say for sure.

[rogelling]

Yes thanks I still have the adapter hoses.