Shoulder season heating question --- DHW

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turfman

Member
Sep 20, 2011
17
western ny
After one year of heating with the Vigas I have come to truly appreciate the gasification heating process, and completely understand the need for storage. I think I have finally located a 500 gallon Lp tank and will soon journey down the road of adding storage, however....

There are days such as yesterday when the temps outside warm significantly and the need for my wood boiler to run is unnecessary so I let the fire go out. When this happens the wood boiler shuts off which shuts the boiler pump off retaining the heat in the wood boiler for HOURS keeping the thermocouple in the wood boiler from tripping (to allow the propane boiler to take over) -- this is where the problem comes in. When this happens my DHW turns cold and the switch over to propane won't happen automatically (wife gets upset!!!), because the wood boiler is holding heat. How do I keep the pump running on the wood boiler to cool the system so that it will switch over to propane automatically?

Hopefully you guys can understand my question -- I was having trouble wording it.

Thanks for any help. I realize this is why storage is so important -- I'm guessing I'll have all sorts of questions when I head down that path. BTW As much trouble as I have had finding a 500 gal Lp tank, is that going to be enough storage?? Is 500 gal better than nothing? Finding another might be close to impossible.
 
500 gallons is a pretty good amount, and is definitely better than none. Other folks here have said that more would be better, but that really depends on your own situation, burning habits, space available, etc. I guess knowing more about your system would really be useful in evaluating if 500 is enough...

For your other question, Im guessing its just a thermostat wire run between the Vigas and the propane boiler? Could you just wire a toggle switch in-line on that wire? That way when you know you want to override the system and have the propane run, you flip the switch and you always run on your backup. I dont know enough about the Vigas controls to know if you can adjust a pump timer setting or something along those lines, I just think about the simple way that I might do something....
 
Sounds like your pump should be controlled by a thermocouple somewhere in the heating supply line rather than in the boiler - or maybe there should be a second thermocouple there that controls when the backup comes on. More details about the system might help - do you have an indirect DHW tank? Is there only the one pump?
 
the system does have 2 pumps - 1 near the old propane boiler in the middle of the house (no basement - slab house) and 1 pump near the Vigas in the garage.

Also 2 thermocouples - 1 at the Vigas and 1 near the manifold in the house (a strap on). The manifold thermocouple has a thermostat wire that hooks to 2 screws on the Vigas and does tell the pump when to come on, as long as the Vigas is burning or "on". The problem seems to be when the Vigas turns "off" or "ends" (when the fire goes out), at this point the system is off and won't let the pump come on.

May well be a programming issue on the Vigas - not sure. Don't know how other systems deal with this.
 
I don't know anything about your boiler, but generally there should be an aquastat or controls that detect the call for heat. If it senses low water temp on your wood unit, it should then start the backup & maybe also its circulator. Don't know if maybe that is something the Vigas should control? Maybe didn't get wired up? Also, once you add storage, something else that should happen is that when the wood unit reaches end of burn, either the pump will run a while longer to get the rest of the heat from the boiler to the storage or it will circulate itself without the pump running to do the same thing. Don't think I'll be much more help on this one...
 
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