Parallel Heating

I have a gas hw system that i want to keep as a back up and i am not sure how to connect this to the efm. help with piping is needed.

here is a start , provide adequate isolations valves , make sure your breeching is in compliance and sutiable for different fuel types and keep needed common piping intact like watermake up, expansion(compression ) tank common to both. Remember a firing pressure vessel with out being tied into the expansion tank or valved off, would in short order blow the releif valve..The scope could be from manual to complete automation.

Hi there,

I have the system you want in my house. It works great! Here's the setup in no particular order.

1. Put a 'T' on the supply and return pipes going up into the house.
2. Install shutoff valves on each side of the 'T'
3. Install a dual junction box with 2 light switch. Each switch will power up and power down the respective boiler
4. Install a 4 gang junction box with 4 light switches. Each boiler uses 2 wires from the T-Stat to the aquastat. Use these switches to switch between your gas and coal boiler
5. Install a 't' coming off of the flue pipe and finish the duct work for each boiler.

That's it. Its simple and works great. I just returned from a vacation down in Florida. Just before I left, I turned off the coal by flipping the shutoff valves and light switches, and did the opposite for the gas boiler side. I set the t-stat at 55 degrees and left the house. Its also fun playing with all these switches and valves. I can pretend I'm in a submarine.

Leo