I am quite unfamiliar with central heating systems, let alone those that use hot water as the heat source, so please forgive my clumsy attempt to ask this question.
I have a First Co Aquatherm "Combo Heater" that is connected to my tank-type gas water heater. As I understand it, hot water is piped in from the water heater to the Aquatherm where it passes through some sort of heat exchanger, producing hot air and cool water.
My water heater recently failed and I had it replaced. The guys doing the install did not check the heating system after they installed the tank; the tech only told me that I might experience some air in our faucets the first time we used the heating system.
The last time I used the heating system (prior to the water heater replacement) everything was working fine - granted this was a few month back in spring. With the new water heater, we get hot water from the tap, but our heating system blows only ambient air. I suspect an issue with the water heater install, but my vendor has washed his hands of it and told me that it's probably a problem with something in my heating system.
I've traced the lines from the water heater up through the ceiling to the Aquatherm in the attic, and from what I can tell they have the connections right. I don't have a way to check that the hot water conduit to the Aquatherm is actually full. My understanding is that the cold water supply provides the pressure for the hot water outlet; this was sufficient before the tank install, so I would assume it's the same now.
Are there any other mechanisms by which a new water heater can cause a heating system like mine to fail? Or should I just shell out for maintenance on my heating system?