[Wardworks]

My Aquahot is blowing cold air out of all of the registers and none of the circulation pumps are working. The burner is working fine and I get plenty of hot water, just no heating function. I tried tapping on things, checked all the fuses, swapped relays... nothing... Any suggestions?

[Trainer]

Rod, checking fuses first was a good plan, bravo.

If you have the very good all metal zone pumps that are mounted three in a row, not plastic, they can loose prime.

To fix this, open radiator cap, fill coolant tank lipping full, distilled water is okay. Install a radiator pressure tester which can be borrowed from some auto supply stores and pump up to 15 lbs. Turn on the zones and feel the brass check valves just above each pump. They should be hot real soon.

Also, a rap on each check valve makes sure they are not stuck. Once open, they will stay loose for the season.

Blowing cool air says the zone plastic relays are good. But a volt meter testing for voltage at the bottom rear contacts makes sure voltage is being sent to the pumps. Very rare for three failed relays at once. The top contacts are for the zone fans which are blowing saiying those contacts are all working.

If you need a little more assistance, call me. 7 one 3 8 one 8 3234

[Wardworks]

Rudy you are the man!

I thought that since none of the pumps were running I focused on it being an electrical issue even though I had never had any pump issues. But when you said "Tap on the check valves if the coach had been sitting awhile they may be stuck shut", that made sense. They in fact were stuck shut and now that they are open there is no back pressure so the pumps can run freely, I have heat through all of the zones.

when I get down your way I will definitely have to buy you dinner!

Thanks again!

[Wardworks]

Well I spoke to soon... The circulation pumps stopped running again. I thought well maybe the check valves got stuck again. So I got out my trusty hammer and tapped on one of the check valves, but this time I noticed that all three pumps came on, which they all should be running since I had all of the thermostats calling for heat. Well one check valve wouldn't effect all 3 pumps so I remembered the other thing that Rudy had said was that something may be wrong with the short wire between the pumps and the relays. Sure enough when I moved the wires under the pumps they would start and stop... Found it! The connectors inside the plastic loom weren't making good contact so when I tapped on the check valves it would shake the pumps enough the wires would make contact and turn on the pumps making me think it was a stuck valve, but in reality it was just a loose connection.

Rudy you're still the man!

[Richard]

I like thermal shrink butt splice connectors because they provide some additional mechanical support to the connection

[Wanderman]

I had a TON of trouble with my circulation/zone pumps. Turned out to be the Motor Brushes needed to be replaced. Once done, they start and stop reliably.

[Richard]

So…….where did you source the brushes?

[Wanderman]

I believe it was:

http://www.carbonbrush.com/springloaded15.htm

But confirm the size with calipers and the length of the spring! Some are different.