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Topic: Aqua Hot Circulating Pumps (Read 2710 times) previous topic - next topic

Aqua Hot Circulating Pumps

I just changed the ignition coil on my Aqua Hot.  It went pretty well.  The contacts on the old one were quite a bit askew from where they should have been and that may have contributed to my original misfire issues.  Put the new one on and aligned the points with the gauge. Fired right up.  All good.
Except... now it seems the circulating pump for the Aqua Hot loops is not working.  It fires and heats up but no heat in the cabin.  Low voltage fans run but only blow cold air.  AND domestic water pump does not work either.  I was going to just make sure the system was hot and when I run water it slowly gets low and the pump does not cycle.  I checked the breakers behind the cover in the curb side bay.  I assume the one marked Aqua Hot runs the pumps as well.  They are both fine.  Is it irony these are both are giving me fits or is there a common solution?  Thank you in advance.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #1 –
Under the Aqua Hot cover located on the face of the tank, there is a fuse for the pumps in the series of fuses above the clear zone relays.  Check those fuses to see if one is failed.  A failed pump fuse stops all zone pumps and no heat to any zone.

Fresh water pressure pump is not a part of the Aqua Hot heater.  Mine has always worked fine so other than a failing pump, I have no idea to assist you.  My pump is located in the passenger side bay just in front of the drive axle.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #2 –
Quote from: Rudy –
Under the Aqua Hot cover located on the face of the tank, there is a fuse for the pumps in the series of fuses above the clear zone relays.  Check those fuses to see if one is failed.  A failed pump fuse stops all zone pumps and no heat to any zone.

Fresh water pressure pump is not a part of the Aqua Hot heater.  Mine has always worked fine so other than a failing pump, I have no idea to assist you.  My pump is located in the passenger side bay just in front of the drive axle.

Yep, I just confirmed that I am an idiot.  Water pump is working.  It was noisy when I was checking and I got all frustrated.  Long story short... domestic water pump works.

I will check those fuses today.  Thank you!

Re: Water Pump and Aqua Hot Circulating Pump

Reply #3 –
Fuses are good.  Pumps sound like they are running.  They are also hot.  Still no heat on any zone.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #4 –
They are magnetic drive, tap on them they might be stuck.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #6 –
Could the check valves at each pump be stuck?  Maybe try tapping on them to free up the flapper?

Re: Water Pump and Aqua Hot Circulating Pump

Reply #7 –
With pumps running, whack each check valve.  Check for valve becoming hot.

If no heat yet, loss of prime is next suspect.

Fill coolant tank at radiator filler neck to lipping full.  Install radiator pressure tester.  Turn all pumps on and pump pressure tester to 15 lbs.  Now check for coolant circulation, ie., heat in each zone.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #8 –
Follow up? Do you have pump working now?

Re: Water Pump and Aqua Hot Circulating Pump

Reply #9 –
Not yet.  Ran out of time today.  Will work on it tomorrow.  Thanks!

Re: Water Pump and Aqua Hot Circulating Pump

Reply #10 –
Was going to add that an air bubble in the line will cause the same symptoms.. Hence pumping the system to 15psi will help move the bubble.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #11 –
If you don't have a pressure tester, one can be borrowed at your local auto parts store.  I got one at O'Riley's. Make sure Aqua Hot is full to the top and your overflow tank is at the correct level.
John M.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #12 –
Small town.  No radiator test kits locally but I think I can rig one with a small air pump.  Any idea where to buy the correct pink/red coolant off the shelf?

Re: Water Pump and Aqua Hot Circulating Pump

Reply #13 –
Your vintage heater uses 50/50 engine antifreeze.  A gallon or two of just distilled water will do just fine.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #14 –
That was my gut feeling as well.  You da man Rudy.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #15 –
Instruction (I actually read instead of looked at the pics) lol

Use an air compressor and blow into the overflow line into the aquahot until the relieve valve pops and that puts pressure on the tank so you wont need the coolant pressure kit  ^.^d

Re: Water Pump and Aqua Hot Circulating Pump

Reply #16 –
Update with instructions from the manual..  ^.^d

Little confusion on my instructions so I am posting the copy of the manual where everyone should look up on there own (never assume).. ^.^d

Re: Water Pump and Aqua Hot Circulating Pump

Reply #17 –
Update:
Tapping on the pumps and relief valves did nothing.
I got 2 gallons of distilled water and borrowed (bought and return) a pressure test kit from Advanced.
Getting fluid into the hole is a pain.  Sounded like it was really empty thus the loss of prime.
It took 2 gallons of water and I still cannot reach liquid 6 inches down from the top of the fill tube.
I park on gravel and looked under and did notice some fluid had drained out around the Aqua Hot exhaust penetration.  And there is some in the pan under the unit. 
I had it serviced last 12/9/19 but they only changed the mixing valve, put new clamps on the fuel lines and put on a new radiator cap.  They would not have drained or lost coolant for this right?
The overflow has always been an inch or two above Cold Full.
Up until this last month or so, the inside heat was working great whenever it was on electric and when the diesel burner was firing.
So, either I have a coolant leak somewhere or it has been low and finally air locked.  The fact that there is fluid under it tells me it is a leak.  So, where is the likely culprit?  Just tell me the whole thing does not have to pulled out... 

Re: Water Pump and Aqua Hot Circulating Pump

Reply #18 –
the tempering valve is on the water side.

Re: Water Pump and Aqua Hot Circulating Pump

Reply #19 –
Quote from: DavidS –
the tempering valve is on the water side.

Correct.  But I'm wondering what else was removed to get to it and how much stuff was pushed and shoved to do it.  or if anything was removed that would have meant losing coolant.  After reading more on here there are some suspect places to look and I am doing that.  The dripping from around the exhaust penetration is my biggest worry right now.