I guess I never realized how much it costs us for domestic hot water. Now that I have the boiler shut down my electric bill is up about $28/month. We don't run a.c. and in the last 30 days there have only been a few days when we ran any fans, so the increase is solely due to the electric water heater. Of course there are a lot of variables such as number showers/baths per day...size of household, actual local market cost for power, etc. When I created a spreadsheet to determine the time period for break even point on the cost of converting to burning wood I missed this cost savings. So it runs us about $154(5.5 months) for hot water when the boiler is off. I wish we had solar.