Hello,

I am a new to this forum, but I have been trying to find a website for some support, so I thought I would give this a try. I had installed a water furnace "evision series" 2 stage, I live in Wisconsin before I forget, it was installed just over a year ago, I built the house 5 years ago and had a propane furnace, so instead of getting rid of a fairly new propane furnace had the installer set it up for use as the back-up heat instead of buying the electric back-up that can be purchased with the water furnace, anyways to the problem, a few cold spells these past few months, made the propane furnace (back-up heat) kick in, it would run for the 10-15 minutes until it brought the temp and then the water furnace is called in to finish the call, this is the way the installer had programed the thermostat, the problem is propane furnace burner shuts off-water furnace pump and fan start-but propane furnace fan is still running until bonnet cools off.....both furnace fans running at the same time, causes alot of noise, also trips the air flow indicator light on the water furnace each time, installer advice get rid of propane furnace, install electric back-up, not the anwser I am looking for....any comments, solutions, anything would be great!

Mostly just advice you don't want to hear.

Scrap the propane furnace. If you insist on keeping it, then consider (I realize it's against furnace manufacturer's recommendations...) installing the heat pump upstream of the furnace. Is your heat pump separate from the blower and coil--the furnace being the blower with just an evaporator coil on it?

I think if you had a switch of some sort that disabled the envision while the propane furnace FAN was running then you would be OK. Find someone who can modify your electronics.