Oil furnace

I have an oil hot water furnace that when its on, runs weather or not heat is needed just to maintain the temp. I want to change it to a cold start system so I can leave it on but not run unless my wood hot water furnace goes cold if I happen to overstay a visit or take a 2 day trip. Right now I have the burner switch off but the house could freeze up if for some reason I can't get home in time. It must be simple to make it a cold start system.
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Van Chocstraw
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It depends upon the other controls, valves, pumps, etc. that are on the boiler. You need some type of device that when energized by a thermostat, turns on it's circulator pump and the burner. It's usually accomplished by a zone valve end switch or switching relay
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Technical detail. Furnaces heat air. Boiler heat water.
Yes, your setup can be changed. Keeping a boiler warm all the time puts less stress on it and makes for faster reaction. If you have a tankless coil for hot water, it is keeping that hot also. These are important for your comfort but not for your situation where it is essentially just a backup.
Do you want to make a permanent change or do you still need the boiler for domestic hot water? I've not played with the controls for a long time so I'm not going to attempt to try and tell you what to change. Meantime, you can set the aquastat as low as it will go to lessen the frequency of starts.
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Won't lowering the aquastat also lower the water temp going through the baseboards? I thought those aquastats controlled both hot water temp and circulating water temp. Plus, to the OP, you mentioned you have a wood hot water furnace?
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Won't lowering the aquastat also lower the water temp going through the baseboards? I thought those aquastats controlled both hot water temp and circulating water temp. Plus, to the OP, you mentioned you have a wood hot water furnace?
The water temp would only be low for a short period of time, once the burner kicked on, by a thermostat. At that point the boiler would rapidly heat and shut off when the zone was satisfied or it reached high limit
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Won't lowering the aquastat also lower the water temp going through the baseboards? I thought those aquastats controlled both hot water temp and circulating water temp. Plus, to the OP, you mentioned you have a wood hot water furnace?
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There are two setting, one for high, one for low. You leave the high point he same, just change the low setting. Not a perfect setup, but would reduce the standby frequency. The controls should be modified to have the burner be activated by a thermostat though, eliminating the need to keep water warm for standby. Then the aquatsat will function with the normal high/low settings
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On Mon, 5 Jan 2009 19:33:56 -0800 (PST), Mikepier

Assuming the wood boiler is in series with the oil boiler, you should be able to turn the min control on the oil boiler down to the point it will not start when the wood boiler is working
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snipped-for-privacy@snyder.on.ca wrote:

It's in series with the baseboard system but in parallel with the other boiler. The wood boiler does not heat the oil boiler water. Each boiler has it's own circulator and there are no zone valves. ANother funny thing is that the wood boiler will gravity circulate so the baseboards are always hot where the oil boiler does not do that.
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If the system only has one circulator and no zone valves on it, then you should have a typical triple aquastat relay on it. All you have to do is what Ed described, turn the low temp "cut in" dial down as low as it will go. In this position,the burner won't kick on unless the room thermostat calls for heat, and provided the wood stove system is functioning, that shouldn't happen
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Ed Pawlowski wrote:

I do not need domestic hot water from the boiler since I have electric point of use tankless units.
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wrote:

So your water boiler that has radiators keeps itself at the aquastat set point of maybe 180f even if no heat is needed all day! If so you sure waste a large percent of your heat bill keeping it hot. The aqua stat on my units is the maximum my HW gets, I set it only as high as I need to to heat. To save now try lowering its temp to the point it wont heat enough then go up 5f at a time, you dont want the pump to run 24-7 either though. In moderate temps I only need 140f, at zero I need about 165f, 180 at - 20f. You will also save by running cooler temps, there are new add on controls with outside thermometers that also do this. I would not want a boiler with hot start, its a waste of money to keep warm. The main energy advantage of new boilers is they hold very little water to heat. Someone at www.heatinghelp.com could tell you how to change it to cold start. I bet you waste 15-30% now keeping it hot
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wrote:

With standby loss, you also probably have a pilot and no auto flue damper something like a System 2000 might only cost you 40% as much to heat your home.
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On Tue, 6 Jan 2009 05:27:02 -0800 (PST), ransley

ransley I think 40% of your brain is pulling 100% of these figures out of your ass. Do you have some written facts to back up all this horse hockey you are flinging around? Im 100% sure you dont. Go figure. Bubba
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Bubba I know 100% of your brain is in the bottle and toilet, you say you are a pro, so learn mr Pro.. Since you are new to the concept of energy conservation do some research on old boilers that maintain high idle water temp, now do research on what a new efficent boiler by itself can save on an old large unit that can hold 6x as much water, that doesnt even have any standard energy saving features. Research what even more modern controls can do. Add it all up and you find it is possible, and I sate Possible, he is wasting 60%. Its possible he is even wasting more with an inneficent Oil burner, soot, poor set up, maintenance and oversizing.
Here in the midwest people take out perfectly good 82% steady state efficent boilers, put in 82-83% rated boilers and save 10-30%, why , because the old ones hold to much water. If you are lucky and have HW and not steam then saving 12% more with condensing is possible. I hate to think what a crap oil unit is wasting compared to new stuff.
You Bubba remind me of my neighbor, I redid everything and was paying 1-120$ a month to heat, he had the same size sq ft house and was paying 6-720$ a month for same type Ng heat. He said its to expensive to do anything and it would not pay back.
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On Wed, 7 Jan 2009 05:17:34 -0800 (PST), ransley

and I know 100% of the figures you are using you are making up on the fly. Your head is quite full of chit. Bubba

no, its because the way they used to rate boilers and the way they rate them now are not the same way. You dont pay too much attention.

So you are telling me that you and your neighbor had the SAME EXACT houses, you both use the same heat producing appliances at the same time, you all use the same amount of hot water, you open and close doors at the same exact time and length of time, you use the same exhaust fans for the same amount of time and you both set your temperatures at the same exact setting? Lifestyles play a huge roll in how much energy you use. You really dont have a clue, do you? Ransley, I do this shit all day everday going on 25 yrs now. You are pulling crap out of your ears that makes no sense. Stick with what you know (whatever the heck that is). Bubba
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