We are buying a house with an oil furnace. The house is from 1940. The oil furnace appears to be about 20 years old and from inspection is in good order. I have never owned a home with an oil furnace and was wondering if anyone has a good source or information about what is involved in maintenance, things to look out for, etc. I have had natural gas furnace and heat pump set ups so the basics around those are familiar to me but zero experience with oil. Obviously I know we have to get a company and come fill the tank periodically but other than that I am a noob. Anyone has any tips it would be appreciated. Thank you.
Buying house with oil heat
- Thread starter RBT
- Start date
Oil heat is very common where I live. Most fuel companies offer automatic delivery and will do the recommended annual service - which normally includes replacing the fuel filter, replacing the nozzle, cleaning the heat exchanger, and a combustion test.
Any idea how old the tank is?
Any idea how old the tank is?
When you say oil furnace do you meat hot air heat or a boiler with baseboard heat.
The oil tank is probably a 275 gallon oil tank in your basement. The oil tanks do get sludge over the years. There are some additives that can help.
The annual maintenance before the cold weather is important. I would not try and do that yourself.
The oil tank is probably a 275 gallon oil tank in your basement. The oil tanks do get sludge over the years. There are some additives that can help.
The annual maintenance before the cold weather is important. I would not try and do that yourself.
The maintenance is straightforward. Filter change, new nozzle, brush out the boiler. Watch a few YouTube videos for your model. Exercise the zone valves periodically throughout the warm season to keep them free.
If you have a steel oil tank know that those things don't last forever and can start to leak. Get a new poly tank. Not expensive but it's going to be expensive to get the old one out.
If you have a steel oil tank know that those things don't last forever and can start to leak. Get a new poly tank. Not expensive but it's going to be expensive to get the old one out.
What other options exist? Is natural gas nearby?
This^ You def don't want a leaky tank. If you have a leak in the basement the smell could permeate the house for years afterward. If you have a leaky tank that's underground you could end up with a remediation bill that rivals the cost of a new car. Tank maint is important.
I have oil fired boiler with hydronic in my log cabin. I maintain the boiler - but pay to have it brushed out every 2 years.
Hopefully you have a popular oil burner like Carlin or Beckett - then any service techs will have needed parts on their truck.
Typical Fall maintenance includes a brush out cleaning, replace the filter at the oil tank, check that the fuel feed line is free of obstruction,
replace a strainer filter in the high pressure pump on the burner, clean the squirrel-cage fan housing on the burner, replace or reset ignition electrodes and gap, clean and check cad cell eye, check flame shape then adjust air and pump pressure (typ 100-125psi) to achieve 0-1 smoke and proper combustion and efficiency and proper draft and pressure differential. No need for a nozzle change if the spray pattern is good. Every nozzle r&r chew up the nozzle adapter.
These units can be fiddly with waxy oil of if the combustion is off. Some techs are just barely capable.
I appreciate low-maintenance natural gas, but I don't like the house-leveling big bang if you have a gas leak or fault.
Ask neighbors who does their servicing and if they have had good results and a reasonable oil bill
- Arco
Hopefully you have a popular oil burner like Carlin or Beckett - then any service techs will have needed parts on their truck.
Typical Fall maintenance includes a brush out cleaning, replace the filter at the oil tank, check that the fuel feed line is free of obstruction,
replace a strainer filter in the high pressure pump on the burner, clean the squirrel-cage fan housing on the burner, replace or reset ignition electrodes and gap, clean and check cad cell eye, check flame shape then adjust air and pump pressure (typ 100-125psi) to achieve 0-1 smoke and proper combustion and efficiency and proper draft and pressure differential. No need for a nozzle change if the spray pattern is good. Every nozzle r&r chew up the nozzle adapter.
These units can be fiddly with waxy oil of if the combustion is off. Some techs are just barely capable.
I appreciate low-maintenance natural gas, but I don't like the house-leveling big bang if you have a gas leak or fault.
Ask neighbors who does their servicing and if they have had good results and a reasonable oil bill
- Arco
Over the last 20 years I spent about 200 euro in maintenance and repair on our 1973 furnace. The burner itself was replaced in the early to mid 80s. I use about 200 gallons of oil per year.
I use some Hercules Sludge Treat at each fill up. I also now use some Fuel Right. My friend had water in his tank. We don't know if someone messed with him (divorce scenario) or just old over time. His tank was in basement but we cleared about 20 gallons of water from it. I used some water indicating paste on my fuel stick after that and had about 2" of water on bottom. That also leads to rust etc. I was using Sludge treat already due to clogged filters when I bought the house. The Fuel Right got rid of the water.
Get first service done by company. Watch and learn. Keep a new filter and nozzle as spare, not hard to change. My first service I had done as I had never worked on Riello burners, just Beckett prior. My filter had to be pried out of housing from sludge, my pump strainer had a thick coat of sludge, the nozzle also had thick coat. Technician said he wasn't sure how it even ran until then. Conversation he knew I had some experience and told me get the spare stuff as I might need to do it again soon but call if needed.
Get combustion chamber and chimney cleaned. Make sure chimney has a cap. I had a sideways heavy rain at old house, with a cap. It still ran down inside and picked up all the crap and dropped it in my boiler clogging the pins. It made for poor combustion that made itself worse, excess pressure inside. I found that Easter Sunday morning when I thought I had a chimney fire, rolling pitch black out of my chimney. I open view port and flames shot at me a good foot. Shut it down, opened up, wire boiler brushed the pins and re-assembled, fired up no issues, ran well. Have chimney checked, my clay liner was crumbling apart and had cracks. I put a stainless sleeve in it, get estimates. I had first company go on roof and say no issue, all is well. 2nd company went up and said falling apart need it done with pretty high price. 3rd company showed up, pickup truck with cap, no ladder on top. He walked around the house didn't go on roof (yet) and said need liner, less price than 2nd company. I said to myself OK yeah right. The guy could see my face and continued to explain. He said you see all these black staining on brick by mortar? That is from cracks inside on the liner. No one else showed me that. He goes to his truck and pulls out one of those extending ladders, hops on roof with camera on a rope and videos the inside and shows me all the issues. He said he uses pickup with cap with that ladder as he doesn't need commercial plates and can take parkways by us. Yup- he got the job right then.
Do you have a separate water heater or tankless coil? Tankless coil wastes a lot fuel. Better to get either an Indirect water heater, possibly electric depending electric cost and if it can keep up. New tankless wall mount water heater or possibly a hybrid/heat pump water heater.
I upgraded old house to new boiler and separate indirect water heater. I added indirect in this house and got rid of tankless coil. I also added a Becket heat manager for the heat and a Field Oil Vent damper to the flue. The OVD shuts and retains heat in boiler instead of 7" hole outside cooling it. Many gas water heaters and others have the same. Both houses going from boiler with tankless coil to indirect water heater, adding the HM and OVD reduced my oil use from about 1200 gallons/year to about 650 gallons. That equites to a pretty quick payback on investment.
You can also upgrade from the felt filters like General 1A wool/felt filters or similar to Beckett/Westwood spin on version.
For reference my boss had/has a sludge issue. His boiler stopped working right before a predicted very cold spell. Service companies not able to make it for 2-3 days. His filter was sludged solid. We put new filter and nozzle, quick clean of the rest, gave him 2 spares of each if needed, he had no issues for months after. Last I knew he was pricing tank replacement as his is inground also.
Get first service done by company. Watch and learn. Keep a new filter and nozzle as spare, not hard to change. My first service I had done as I had never worked on Riello burners, just Beckett prior. My filter had to be pried out of housing from sludge, my pump strainer had a thick coat of sludge, the nozzle also had thick coat. Technician said he wasn't sure how it even ran until then. Conversation he knew I had some experience and told me get the spare stuff as I might need to do it again soon but call if needed.
Get combustion chamber and chimney cleaned. Make sure chimney has a cap. I had a sideways heavy rain at old house, with a cap. It still ran down inside and picked up all the crap and dropped it in my boiler clogging the pins. It made for poor combustion that made itself worse, excess pressure inside. I found that Easter Sunday morning when I thought I had a chimney fire, rolling pitch black out of my chimney. I open view port and flames shot at me a good foot. Shut it down, opened up, wire boiler brushed the pins and re-assembled, fired up no issues, ran well. Have chimney checked, my clay liner was crumbling apart and had cracks. I put a stainless sleeve in it, get estimates. I had first company go on roof and say no issue, all is well. 2nd company went up and said falling apart need it done with pretty high price. 3rd company showed up, pickup truck with cap, no ladder on top. He walked around the house didn't go on roof (yet) and said need liner, less price than 2nd company. I said to myself OK yeah right. The guy could see my face and continued to explain. He said you see all these black staining on brick by mortar? That is from cracks inside on the liner. No one else showed me that. He goes to his truck and pulls out one of those extending ladders, hops on roof with camera on a rope and videos the inside and shows me all the issues. He said he uses pickup with cap with that ladder as he doesn't need commercial plates and can take parkways by us. Yup- he got the job right then.
Do you have a separate water heater or tankless coil? Tankless coil wastes a lot fuel. Better to get either an Indirect water heater, possibly electric depending electric cost and if it can keep up. New tankless wall mount water heater or possibly a hybrid/heat pump water heater.
I upgraded old house to new boiler and separate indirect water heater. I added indirect in this house and got rid of tankless coil. I also added a Becket heat manager for the heat and a Field Oil Vent damper to the flue. The OVD shuts and retains heat in boiler instead of 7" hole outside cooling it. Many gas water heaters and others have the same. Both houses going from boiler with tankless coil to indirect water heater, adding the HM and OVD reduced my oil use from about 1200 gallons/year to about 650 gallons. That equites to a pretty quick payback on investment.
You can also upgrade from the felt filters like General 1A wool/felt filters or similar to Beckett/Westwood spin on version.
For reference my boss had/has a sludge issue. His boiler stopped working right before a predicted very cold spell. Service companies not able to make it for 2-3 days. His filter was sludged solid. We put new filter and nozzle, quick clean of the rest, gave him 2 spares of each if needed, he had no issues for months after. Last I knew he was pricing tank replacement as his is inground also.
Last edited:
I also pay cash/charge/COD for oil from local company. I do my own maintenance though but $.50 or more gallon covers a lot quickly. If you don't know how or have concerns a maintenance contract might be nice for when you are not home but significant is cold and no hot water.
Depending on where you are, and if the design of the house allows, I'd consider putting in a mini-split system to handle the bulk of your heating needs... and then use the oil furnace as auxiliary heat, only when it gets extremely cold. Double bonus if the house currently doesn't have any A/C.
I've lived in two houses with oil heat. They'll get the job done, but the oil can get expensive after a while.
I've lived in two houses with oil heat. They'll get the job done, but the oil can get expensive after a while.
I was thinking of adding a spin on fine fuel filter in line after the foam or string filter canister to keep the feed line and pump strainer and nozzle filter tidy.
The service guys that do the brush out say no don't do it - but I am thinking yes.
The service guys that do the brush out say no don't do it - but I am thinking yes.
Being that unit is from 2000, it's not very efficient anyway. Burns alot of fuel. The new models are much more efficient, and will save you money on oil, which is not cheap. I would also get a separate hot water tank to cut back on fuel costs. You're best bet is to find out if there is a natural gas main nearby, have a line run to you're house, and switch over to gas. It's cheaper in the long run. Get a natural gas hot water tank also. Whichever way you go will cost money up front, but will save you money in the long run. As for the tank, if you stick with oil, and it's steel, use the above treatments in it to keep it clean. Definitely get a service contract if you're going to stick with oil, this way they can do the maintenance on it. Then just have an electric hot water tank installed. I've seen steel tanks installed outdoors. I could imagine the sludge built up in them due to weather/humidity/cold temps. Glad I have natural gas. Pretty much maintenance free, and no delivery concerns.
Fuel oil is one of my companies specialties. We service hundreds of oil fired furnaces and boilers every year.
My advice would be to have the system serviced yearly by someone who actually understands fuel oil. Talk to your local oil supplier and see if they can recommend anyone.
Also keep an eye on your tank level and try to avoid running out of oil. If you run out the system will have to be bled to get the air out of the lines and pump. If you are mechanically inclined its not hard to do. Sort of like bleeding brakes. 10 gallons of diesel fuel will get you up and running for a few days until you can get a delivery of oil. Fuel oil is just off road diesel fuel.
My advice would be to have the system serviced yearly by someone who actually understands fuel oil. Talk to your local oil supplier and see if they can recommend anyone.
Also keep an eye on your tank level and try to avoid running out of oil. If you run out the system will have to be bled to get the air out of the lines and pump. If you are mechanically inclined its not hard to do. Sort of like bleeding brakes. 10 gallons of diesel fuel will get you up and running for a few days until you can get a delivery of oil. Fuel oil is just off road diesel fuel.
Oil furnaces have not changed much in the last 25 years. 80 to 86 percent efficiency is all you get. One from 2000 will run just as efficient as one installed yesterday if the burner is setup correctly.
Underground oil tanks that develop leaks can be problematic and depending on the state rather expensive to remediate if discovered
Thank you for the help. We have an oil burner with hot water heat and two zone AC. The AC for the new extension of the house is already a heat pump and when the AC for the original part of the house goes south (it’s a carrier so may be a while) I will install a heat pump.
The house is a long distance from the street so a natural gas line, even if available in the road, is not going to be cost effective.
I will hire an oil company to deliver the fuel and give the burner a service. The house was well maintained but it is an estate sale so we don’t have the full history of what was done when, only what we can intuit.
Thanks again for the help.
The house is a long distance from the street so a natural gas line, even if available in the road, is not going to be cost effective.
I will hire an oil company to deliver the fuel and give the burner a service. The house was well maintained but it is an estate sale so we don’t have the full history of what was done when, only what we can intuit.
Thanks again for the help.
Call around oil companies. The was a COD (that was their name) oil company that delivered oil for cash. Then full service. The full service auto delivery use degree days and prior usage to determine when to deliver. You can also prepay and budget and contract.
Oil does not need to be an expensive way to heat. It depends on the condition of the house (insulation & windows/doors).
The cheapest way to heat a house is to not live in one of the cold areas of the country.
Make sure to vacuum under the baseboards. The heat from them works by natural convection of heat across the fins. My dog sheds liek crazy and the hair just gets everywhere under there. I put my shop vac on the bottom with crevice tool and put a smaller line on exhuast of it. I use that to blow down from top into the crevice tool area.
I use my heat pump/central air to help circulate the air. My heat pump is set about the same temperature and I have the fan set on "circulate" for 10 minutes every 70-80 minutes. Keeps all moving and more even. When it's really cold like 25 degrees or lower and windy, I turn heat pump down 1 degree so hot water kicks in first. Freezing pipes sucks and is a real thing in many places and just takes a small air leak by a pipe.
Depends where and when. I know many years the overall costs by me were close. Many years from talking to friends that have very similar house, their gas cost was higher than my oil cost. Difference is I need to pay when filled up, they get monthly bill.
