pughimag

Jim, Thank you for your great response. I have contacted two HVAC specialists for a quote but I like to do my own work when I can. I am an electrical engineer and I spent half my life fixing machines of one kind or another. I do like to do it right however. I downloaded a pdf doc on the Apollo units and I've been taking things slowly. I had one company call me to do maintenance work. All the guy did was check the current in the pump in each air handler and for that he charged me $150. That experience raised my hackles somewhat. I was expecting him to clean the coils and check the drains also. Marc, no heat pumps involved just two compressor units outside and two air handlers inside for the cooling/heat exchange portion. The heat comes from the two Apollo gas-fired heaters in my garage. There's an additional coil that handles heat exchange in the Apollo air handler unit.

I have a Hydroheat MA 4230 which is installed horizontally in my attic and has an intake plenum which is sealed with a grey sealing compound of some kind, making it very difficult to get to the input side of the condenser coils so that I can clean them. I do not want to break the seal to remove the end panel but this seems to be the only option. I can slightly open a panel on the side of the unit (where the freon pipes enter)and I see the V-shaped coils (some rust there) but I can't really reach in to clean them. Any advice please? I also see about an inch of water in the bottom of the inside so I'm going to check the evaporator drain (no secondary is plumbed). I think there may be some mold in there also so I would like some advice as to how to get rid of it. I turn off the thermostat before removing the panel screws. From what I've read here I should also check the blower and turn off the breakers to be safe. I am getting cold air but I know the coils have not been cleaned for years so I would like to make sure the job is done well. Any advice would be appreciated. On the output side the evaporator coils show some rust at the edges but the heating coil input side, which is next in the plenum seems to be ok, just needs a little cleaning. I suspect most of the dirt is on the input side of the condenser coils. I have purchased a spray can of HVAC cleaner from Home Depot.