Aqua Hot Zone problem

junglturbine · 09-06-2011, 05:29 AM

Having zone problem with Aqua hot heating system yesterday.
Front zone heats well but zone's 2 and 3 (running off snd thermostat) only blow cold air. Is there something simple that I'm missing?

Thanks

Mike Canter · 09-06-2011, 06:10 AM

Most likely the one way flow valves are stuck closed on the water lines coming out of the top of Aqua-Hot unit. Tapping the valves lightly with a brass hammer will make them open again. No point in changing them because it will happen again with the new ones. The biggest thing that causes that is having the boiler anti-freeze to water ratio wrong and having too much anti-freeze. Instead of a 50/50 mix you may have a 55/45 mix.

djhinds · 09-06-2011, 06:13 AM

Down on top of my Aquahot are the valves for each zone. Tap on them while it is calling for heat. Sometimes they stick shut.

Dave
Monaco Signature
Detroit 60
Honda CR-V

series60man · 09-06-2011, 08:26 AM

Make sure the pump that delivers to that zone is working.

sparkydog · 09-06-2011, 01:28 PM

Mine HR Imperial had a bad circuit board, everything worked except zone 1, would not heat. Called factory, they gave pins to check on the board, sequence to check all pumps to isolate problem. Replaced the board, all is fine albeit expensive fix. About$450 plus shipping.

Mike Canter · 09-06-2011, 02:09 PM

It is very common for these one way valves to stick shut if the system has not been used in a while. Yes, first you can select for heat all the zones then look at the AQ electronic board and see if it has green LEDs for all the zones. Or you can open up the AQ unit around the burner select for heat all zones and take a flashlight and see if the pumps are spinning. If the pumps are spinning then tap the brass inline one-way valves above each pump and you will get heat in those lines

Drifter · 09-06-2011, 03:58 PM

When we were Yuma last year I helped a guy with a Country Coach fix the Aqua Hot by installing a swing check valve that was disabling a zone in his system. The valve can be had at almost any hardware store. If you order from the Aqua hot people you will pay much more than double plus shipping and it will most likely be from China. Just use clamps on the hoses to block fluid from draining the whole system and replace valve, very easy.
Here is a link:Swing Check Valve, 1/2 In, FNPT, Brass - Check and Foot Valves - Valves - 6NN92 : Grainger Industrial Supply

Mike Canter · 09-06-2011, 04:04 PM

Mike, according to Aqua Hot, it is a waste of time to change them because they will stick again. The other option is to take them apart and clean them. I believe you can open them up and pull out the flapper valve and pull out the shaft and clean them and put it pack together with doing what you say and that is just clamping the lines. According to Aqua Hot the biggest reason they stick is like I said before and that is the wrong percentage of boiler antifreeze mix. If it is to strong it makes them stick. I usually have to tap one valve at the start of the cold weather then it is good for the winter.

Mike Canter · 09-06-2011, 04:16 PM

Sorry, forgot. Here is the actual valve used. It is a little different than the one listed in Graingers. Not sure which one is best. The website is in the upper right corner of the attachment. This actual valve is also available through MSC Industrial Supply and their part number is 36895316 at $11.25 each.

Drifter · 09-06-2011, 08:58 PM

Mike, The Country Coach I worked on was a 2008 with 4000 miles on it. The Aqua Hot system in that coach had the bronze not brass made in China. I guess Aqua Hot is also cutting costs. The guy was waiting for parts when I met him, and he was paying 41.00 from Aqua Hot. I bought a Mueller Brass one for 4.95 at a local hardware and fix it before the service tech came back to save him the 125.00 service call. My service call charge was a twelve pack of Ultra. But some only trust techs, I just like to help.

junglturbine · 09-08-2011, 08:34 AM

Thanks everyone for the input.
The two zone's valves were stuck and a light tap opened them and all is well. Nice easy fix.

Mike Canter · 09-08-2011, 09:23 AM

Yes, it is a annoying problem but cheap to fix. If the valves had been installed horizontally vice vertically I doubt that we would have the problem. I am surprised that the pumps do not make enough flow to open the valves. One thing I was going to check is if there was a difference running off the batteries without the charger on at 12 to 12.6 volts or with the charger on putting out over 13 volts. If that higher voltage would speed up the pumps enough to free the flapper. Like I said you should verify the antifreeze to water ratio and the only way you can do that is with a refractometer such as this.
Robinair Mfg Corp 75240 Coolant and Battery Refractometer#

series60man · 09-08-2011, 05:08 PM

I have current at one pump but it does not turn. Has anyone found a cheaper pump that Aqua hot. They seem to be far more expensive than other small pumps. I would rather replace several $50-80 pumps than one of theirs.