I replaced the control box in the aqua hot the end of November. I put it in, made sure it cycled off and on and then had to leave the bus for two weeks.
The old one is on top and the new one is below. It looks completely different but plugs up the same. I ordered it from Prevost.
I left the thermostats set to come on and instructions for my dad to turn the aqua hot on if the temps went down to a certain level. The weather was nice while we were gone so he did not turn it on.
When we arrived home the low was about 20 that first night so we turned it on. We have electric toe kick heaters and heat strips in the roof airs as well so we do not have to have the diesel heat in the living areas. I run it mostly to heat the plumbing bay and it does get it toasty inside real quick and the other heat sources can maintain from there.
I have two heat exchangers up front controlled by one thermostat behind the drivers seat and two heat exchangers in the back contolled by a thermostat by the bed. The ones in the back work perfectly and the ones in the front blow cold air.
I have not taken the cover off the aqua hot to examine anything yet. I know each zone has a circulation pump and I can feel if the one for the front is kicking on or not once I get down there. I thought I would ask for tips here before I crawled in the bay.
Any chance my new control box is causing this? My dad repaired the relay that was burnt in my old control box so I am tempted to put it back in and see if that solves the problem. I know the front zone was working during a cold snap in Oklahoma in October or November.
Any other ideas or things to check are appreciated.