Gas and Oil Home Heating Furnaces - Can Oil Furnace Be Turned Off?
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CTGrandma
07-15-09, 02:31 PM
I have a bet with my husband. Someone told me that you could turn off your oil fired furnace during a vacation in order to save oil. This would be done as the hot water comes directly off the oil burner and if no one was at home, the furnace would not need to make hot water. My husband said you definitely cannot do this as the seals inside the burner would contract and then expand upon firing it up again. This would cause the seals to break down or malfunction. Who is correct?
furd
07-15-09, 03:34 PM
You're both right and you're both wrong. (How's that for a weasel answer> :D)
What you have is not a furnace but a boiler, but no matter as my mother could never understand the difference either. Yes, you certainly would save oil in not keeping the boiler hot 24/7 but since most residential boilers are made up from cast iron sections your husband is also correct that often (but not always) allowing a cast iron boiler to cool to room temperature will cause them to leak. Will it actually destroy the "seals" over time? Maybe since some boilers use what the manufacturer calls an "elastomeric seal" but is probably an O-ring. The more common cast iron boiler uses what are called "push nipples" and they would probably seal again when the boiler temperature is again raised.
The "tankless coil" in your boiler is (in my opinion) a very poor way to heat domestic hot water. It is only slightly better than an open kettle on a wood-burning kitchen range. A far better method is with what is called an "indirect water heater" that is a separate highly insulated tank that is heated from the boiler water. This allows the boiler to cool back to room temperature when no hot water is being used. It may (or may not) be compatible with your current boiler.
What you have is not a furnace but a boiler, but no matter as my mother could never understand the difference either. Yes, you certainly would save oil in not keeping the boiler hot 24/7 but since most residential boilers are made up from cast iron sections your husband is also correct that often (but not always) allowing a cast iron boiler to cool to room temperature will cause them to leak. Will it actually destroy the "seals" over time? Maybe since some boilers use what the manufacturer calls an "elastomeric seal" but is probably an O-ring. The more common cast iron boiler uses what are called "push nipples" and they would probably seal again when the boiler temperature is again raised.
The "tankless coil" in your boiler is (in my opinion) a very poor way to heat domestic hot water. It is only slightly better than an open kettle on a wood-burning kitchen range. A far better method is with what is called an "indirect water heater" that is a separate highly insulated tank that is heated from the boiler water. This allows the boiler to cool back to room temperature when no hot water is being used. It may (or may not) be compatible with your current boiler.
CTGrandma
07-16-09, 05:08 AM
Thanks for your reply! We are actually looking to buy a new boiler in the next year. Could you please point me in the right direction of what I should be looking for? As this is going to be a large expensive purchase, I would like someone's opinion on the makes, models, etc. that I should be considering.
daddyjohn
07-16-09, 05:43 AM
How much is the bet? he he
furd
07-16-09, 01:52 PM
CT, my experience is with commercial and industrial sized equipment so I can't make any recommendations. However, there are some VERY well informed people on residential systems that love answering questions concerning new equipment on the boilers forum located just above this one. I suggest that you review some of the posts on that forum and ask your question in that forum. I guarantee that you will receive more information (and good information) than you could ever imagine.