Mothballing an oil fired boiler

[zak77]

So i have a 32 year old Peerless boiler for FHW heat for my house but i burn wood so i will very rarely ever need heat from this boiler. I switched the domestic hot water over to a hybrid water heater years ago. This past summer i spent $800 on fuel and repairs/cleaning but i've come to the point where i find i'm throwing money away and would prefer to shut this down completely a put money towards a new boiler at some point. I am not really concerned about being able to use this boiler in the future so i'm going in assuming this will be junk. I will hopefully be installing mini-splits for supplemental heating in the fall/spring.

So what is the preferred method to mothball this boiler? Obviously i'll run it till the oil tank is almost empty then kill the power to it. Shutoff the valve at the oil tank, remove and clean filter housing, then blow out oil line? Of course i'm aware of the remaining oil in the tank being a potential problem if i install a new oil boiler at some point so i'll deal with that in the future. Next would be draining the system of all water. I debated whether leaving water in the boiler would be better or worse than draining it but i'm not sure so here i am. Any advice someone can offer, i'd appreciate it.

 

[yeldogt]

The question is what will the new boiler give you ? When you had the unit serviced did they give you an efficiency rating? Not a huge advancement w/ oil -- especially boilers. It's a tank of water and a burner ? There are 50-60 year old boilers out there chugging along -- so if there is nothing wrong with it now after whatever you did to it ... replacing is for what?

I had a big old place in chestnut hill -- Moses had installed the boilers. The old guy from the oil company told me I was not going so save any fuel with the two shinny Buderus boilers I picked to install. I was redoing the heating systems after owning it a couple of years.

He ended up being correct -- this was back in the 90's and not much has changed in the oil world. You just need a decent burner and they are replaceable.

IMO -- you are better off running it occasionally vs shutting it down

 

[zak77]

84-86% efficiency, from what i can recall. Considering the changes and advancements in heating technology, if i decide to replace the system in the future it very well may not be oil fired. I'm seeing a fair amount of people ditching their oil fired appliances and switch over to mini-splits or propane for heat. The constant cost of keeping this running is my main issue. I've owned the house for 13 years now and maybe turned the heat on to warm up the house maybe a total of 20 times. One issue i do have, found it when i would shut it down for the summer, is that the plate for the hot water coil(disconnected) would leak a little when the boiler cooled down. I did intend to replace the plate but the very good possibility of having to deal with broken bolts and removing them didnt encourage me to tackle the project.

I hear you on the older boilers being almost indestructible, my parents had a General Motors boiler in their house back from the 50's, that worked just fine. As long as i can, i plan on burning wood in this house, but if i ever decide to sell it, having a new boiler, whatever is firing it, is a big selling point over a 32+ year old boiler run by oil. So even if i replace it with another oil boiler, or change it over to something else, it'd only be a beneficial selling point and add to the market value of the property.

 

[65ranchero]

I have a HW boiler and I run my heat @65-67 F in the winter in 2200sf - Radiant heat in garage work shop and have a indirect DHW tank next to it
efficiency is around 85-87% So the boiler is never shut off . 850-900 gallons a year. I'm happy
The way my house is set up, a wood stove is not a good accessory ( although at a cost it could be done), no room in the chimney to run a separate flue and I'm not going to run another chimney through the roof ( brand new 4 day old Standing Seam roof.)

Oil service guys would say don't get rid of it ,keep it as long as you can the newer ones break down more Parts are harder to get
If I could, I would switch to NG but that is not a option for me.

In my other house I has a Weil-McLain HW boiler and I would shut it down in the spring, no draining or any fuel maintenance and the in the winter flip the switch and all is good.

 

[yeldogt]

In a modern house w/ tight everything you may like a mini split .... in an older house that leaks -- forget it. There is nothing as comfortable in an old house as a some type of hot water heat ....

Will you get the return on a new heater ... depends

 

[finn]

Circulator pumps will eventually seize up if you don’t run them on a regular schedule. Never heard of problems with the fuel pumps due to inactivity, though.

 

[Jackfre]

What is the condition of the tank? If mine I’d have it cleaned, set up and run at least weekly to keep it in shape. Set the stat low for protection. Oil is great heat but its day is about done. I belong to a couple private oil and gas sites and the word from them is oil and LP stocks are all ready low, thanks to Vlad the Impaler, so pricing may get wild this winter. When faced with an existing system in a home and looking to go to mini-splits I say, Don’t replace. ADD. Install the mini-splits, keeping Yeltdog’s caution in mind, as you may need to do some weatherization. With wood, oil and ms you should be covered When the minisplits show they can carry the load, then get rid of the oil if you choose.

 

[fitter30]

Keep the water in it but treat it to the color violet with Rectorseal-68712-8-Way-Boiler-Water-Treatment works for either steam or hot water. Biggest problem is oxygen one little air bubble an corrode a hole through the boiler. Treatment has a oxygen scavenger and scale inhibitors in it.

https://bit.ly/3aB9yLL