QHT Boiler manual boiler

for the dump zone.

3. Install a tee with a 1”branch coming out of the supply tapping of the 3WOOD

C.3WOOD Boiler with circulator Piped in Parallel with Oil/Gas Boiler

In the traditional American baseboard, hydronic system, the heating temperature in the house or zone is controlled by circulating or not circulating water of a fairly high and relatively constant temperature to radiation. The thermostat used in such a system is a simple switch to a relay which turns the circulator on and off. The vast majority of American heating systems use cast iron boilers which have internal tankless coils for producing domestic hot water. The parallel piping arrangement is the correct application for maintaining temperature in the oil/gas boiler with wood heated hot water as well as heating the radiation in the house. Since the specifics of such a system will vary from installation to installation, the following procedure provides an example of one specific installation which can be used as a model for actual situations.

1.Insure that the existing system has flow checks or electric zone valves in the supply lines to the various heating zones, and that the Space heat and DHW circulators are mounted on the return line going back to the Oil/Gas boiler. If not, they must be installed in these locations.

2.Remove the existing radiation supply and return lines from the oil or gas-fired boiler. Install pipe tees on the supply and returns from nipples coming out of the existing oil/gas boiler. NOTE: Occasionally, extra supply and return taps are available on oil/gas boilers. These plugs may be removed and used to run the lines between boilers. Re-install the supply and return lines.

4.Then install another tee with a ¾” branch for the Aquastat for the 3WOOD into the branch of the tee using the 3/4 “ immersion well. Caution: Be careful flue pipe and the 3WOOD boiler aquastat.

5.Pipe from this tee to the supply pipe on the existing oil/gas boiler.

boiler

boiler’s circulator. Install the Honeywell L4006B to maintain a 12” minimum clearance between the

Note: By adding the gallonage from the addition of the 3WOOD boiler, an expansion tank should be added or the existing tank should be increased in capacity.

6.Install a tee with a 1” branch coming out of the return tapping of the 3WOOD boiler for the dump zone.

7.Install piping, flow check and circulator from 3WOOD boiler to the return manifold installed on the oil/gas boiler.

Note: Aquastat settings for the existing oil/gas boiler should be as follows: High Limit – 165F

Low Limit - 150F Circulator - 140F

But these settings can be raised if the 3WOOD boiler isn’t fired for extended periods of time.

29