Using an inverter on a CH boiler

[Harveybaxi]

I would like to be able to power my Baxi combi CH boiler via 12v inverter in the event of a mains power failure. Has anyone any experience of this?

 

[electronicsuk]

If it's a cheap inverter with a square or, more commonly, modified sine output, then the pump may be unhappy running on it. Anything other than pure sine can lead to excessive power dissipation causing some electric motors to overheat or run noisy.

Either buy a pure sine inverter to assure yourself that it will work (and make sure the peak power capacity is high enough to take the peak load of the boiler when the flue fan/pump start up!) or try a cheap inverter and see what happens.

 

[Harveybaxi]

Thank you Electronics UK.

I had it in mind to use a pure sine wave inverter with plenty of capacity but you have now given me the confidence to go ahead.

Harveybaxi

 

[electronicsuk]

Thank you Electronics UK.

I had it in mind to use a pure sine wave inverter with plenty of capacity but you have now given me the confidence to go ahead.

Harveybaxi

Glad to have helped. If it puts your mind any more at ease, I fitted a 10kVA UPS at my previous house to provide backup on lighting and power circuits. This had pure sine output, and I had no problems running any kind of load on it, including a modern boiler.

 

[kenfyi]

For the past three years, during at least six power outages, I have run our U.S.-made Weil-Mclain gas-fired boiler with a "Honeywell dual valve intermittent pilot combination gas control" by disconnecting the 24 V transformer from the house line and powering it via a 12 V car battery hooked to a Vista CXV solid state power inverter that gives 115 VAC, 60 HZ SQUARE WAVE, 200 watts continuous current. There is a small "Effikal" automatic damper motor in the loop as well, that opens the flue just before the gas fires up the boiler. Never had a problem during or after using this bypass method. The car battery will run it for about 24 hours, or longer if you keep dashing to the furnace room to turn the inverter off until you actually need heat. Since our outages sometimes go for more than a day, I keep two batteries charged up all the time. You can buy a pure sine wave inverter if you have that much extra money, but you may not need it if your heating plant is anything like mine.

 

[kevplumb]

glad i dont live there our outages dont last much over 2 hours

3 auto batterys on a trickle charger