We have a hot water (baseboard) heating system with an Weil-Mclain oil fired hot water boiler. The house is 40 years old and the boiler is 10+ years old. It's a 3 zone system, 1st flr, 2nd flr, and garage.

The boiler is not maintaining the 180 deg internal temperature and therefore not able to heat the house. Even though the thermostat is calling for heat, the boiler is not firing up to heat up the water. The problem is intermittent but is happening frequently.

My solution is to manually start the burner by pressing the red reset button on the Honeywell controller box which usually results in the burner firing up. The systems runs normally for some time.

I've called my service company 4 times in the past week - it always seems to act up off-hours during the weekend - and they've come out each time, performed some type of service and left with it running just fine. Yet hours afterwards the boiler goes cold again requiring another manual restart.

The first time out, the tech performed a burner service -filter, nozzle and strainer. Second time, replaced CAD cell, checked transformer, cleaned contractor and adjust air. Third time, "adjusted the flame". Fourth time, the tech checked the pressure on the lines from the out tank and found they were at 20lbs of vacuum - which he said was too much. Attempted to clean the lines using CO2 and manually. Got the pressure down to 15lbs. When he left the system was running fine and the house was warm! Several hours later, once again, the boiler temp reads <80 degs, the house is getting cold, and I have to hit the reset button to start it up.

I'll call the service company back tomorrow. Not sure what they'll do next.

Any suggestions would be appreciated. Thanks.

 

Sure does sound like an issue with the tank or line.
The tank does need to vent.. has the vent pipe been checked ? If your fill cap is a simple fitting with a thumb screw, then there's probably enough vent there.. if it's a threaded on cap, then the vent pipe certainly needs to be working.
Possibly water freezing in the line ? Is this an above ground tank ? Does this just happen during a cold snap ?
Crud /sludge in the tank partially blocking the line ? Theres some tank additives like SludgeBeGone that attempt to break down sludge and carry it down the line. Some gets stuck in the filter, some is small enough to pass thru and be burned.
How much fuel do you have in the tank ? A full tank will require less 'pull' from the burner pump. If you are down to like 1/3 or 1/4 full, it would probably be worth checking. If your pump is getting tired, maybe it cant 'lift' from a mostly empty tank very well ?

 

Where is the tank located (above or below the burner? How far above or below? What is the height difference? How far from the burner? ) Is it a 'top feed' or a 'bottom feed' ? Are there two pipes from the burner to the tank?

What did the filter look like when they changed it?

Did they check/change the strainer screen inside the pump?

 

I'll try to answer the above questions as best as possible...

Not sure if the vent pipe was checked. I think the fill cap is a threaded on cap.
I don't think water freezing is an issue. I'm in NJ and the outside temp has been unseasonably warm, especially during the past week when all this occurred. On the 4th service call, the tech was suspicious of the lines and in addition to using CO2 to blow them out, he told me that he put some additive/cleaner into the tank. The last fill up was back at the start of Feb, about 1 month ago now.

This problem first occurred about 1 month ago. I pushed the reset button and it fired up and had no problems until last weekend. So, the problem has only occurrred during winter, a mild winter though!

I've read online that you should shut the burner off during an oil delivery and leave it off for a few hours afterwards to allow time for the sediment and crud to settle back down. The oil company has never suggested this and delivers fuel to the house un-announced - so there is almost no chance of me or my wife shutting it off.

The tank is below ground in my front yard. The burner is in the basement also below ground. I would think they would be about even. They are about 30' apart and there are 2 lines that run from the tank to the burner. The filter was pretty dirty when it was changed last weekend on the first call. Note the burner had its annual tune-up back in early November. Not sure if the strainer screen was checked or changed but the service slip indicates the strainer was replaced.

 

How long has it been there ?

Get it out of the ground, SOON! and pray this doesn't happen to you:

Oil Tank Remediation pictures by JeffPicks - Photobucket

(the truck isn't really in the hole... photoshopped in for size reference)

If you've got 15" of vacuum, there's still a problem. There's probably a foot of sludge in the bottom of that tank. The suction line is probably down into the sludge in the bottom.

 

The tank has been there since the house was built in the lat 70s (1978?). I have oil spill insurance coverage through Tank Easy of NY. They came out last year to inspect the tank before they wrote the policy. They did not mention any issues. I did have a hard time finding a Homerowners Insurance policy when I bought the house years ago. Most Ins Cos did not want to write a policy for a house with an inground tank.

What is a ballpark estimate ($) to remove the inground tank and replace with a basement tank? Its right under my front lawn, no issues with access.

Just spoke to the ownerer of the oil service company that is working on the problem. They want to come back and try to clear the lines using compressed air and some type of chemical solvent through the lines. They also will inspect the tank to determine how much sludge is in it and if it should be cleaned with a chemical or mechanical.

 

Check to see if NY state has an incentive plan to encourage tank removals. Here in NJ they will give a grant of up to $3000 or so if you have a NON-LEAKING underground tank removed and replaced, and it's a little complicated to apply for, but I know several ppl who got a check.Guess what? That's almost exactly what it costs here in NJ! I wonder why? hmmm...

I think if you budget $3000 you should be fine, but shop around and CHECK REFERENCES AND LICENSES AND INSURANCE CERTS!

Here's some info on NY State that may prove helpful:

Underground Heating Oil Tanks: A Homeowner's Guide - NYS Dept. of Environmental Conservation

One possible caution... IF there are rust 'boils' on the bottom of the tank now, and there is heavy sludge inside the tank covering them, one should probably be wary of banging stuff around inside the tank... so make sure they know what they are doing!

My advice is to bite the bullet and get the thing out, it's a liability no matter which way you look at it. If you decide to sell at any time in the future, don't be surprised if potential buyers turn tail and run when they learn that there's a UST on the property. Talk to realtors you may know, I bet they say the same thing.

 

I concur with Trooper, especially if there are any governmental incentives (monetary grants) to help cover the costs. You DO NOT want to do any mechanical cleaning for the exact reason Trooper gave, it could make the tank leak if it isn't already leaking.

Where I used to work we had three 25,000 gallon USTs (Underground Storage Tanks) and new regulations required them to be cleaned and certified along with the installation of a leak detection system. I don't know how much money was spent on cleaning, shot blasting and epoxy lining the tanks along with the leak detection system but it wasn't five years later that they dug them up and replaced them with three new double-wall tanks and double-wall piping systems along with a new leak detection system. I think the replacement ran close to $100,000 and the ONLY reason the new tanks were buried was there was no place to have above ground tanks of sufficient capacity. There were many gasoline stations that went out of business when the new rules went into effect and their tanks were not leaking.

I guarantee that it will never get any less expensive to remove the tank. Do it now before you have problems or the current problems get worse.

 

Thanks to ALL for the great advice so far....

The oil service owner wasn't pushing for the tank clean-out... just the chem treatment. Didn't mention the possibility of a tank removal. I'm aware of the problems this may cause down the road, especially if I try to sell the house.

NJTrooper... I'm actually in NJ (Essex Co.), not NY... its just that the tank insurance was purchase from a NY company. Any specific advice related to NJ would be appreciated.

 

ahhh crap...

NJDEP SRP - The Petroleum Underground Storage Tank Remediation, Upgrade And Closure Fund (UST Fund)

If I'm reading this right, I need to stay on top of the news. I'm sorry to say that it appears that they've lost their funding since May of 2011... sorry about that!

But look the info over well, read the fine print, there still might be some hope that they get funded again although this doesn't sound too hopeful:

 

My in ground tank is 35 years old. Its 8 feet from the house. I replaced the copper lines 5 years ago myself. I was surprised how easy it was. They use brass parts to attach the lines so rust wasn't an issue. I made them a little shorter than the old lines. The old lines only had about a pinhole size passage remaining.

 

I have to agree about getting rid of the old tank but let's address the high vacuum problem:

Installation of a Tigerloop will reduce the strain on the pump dramacitally. I wouldn't be surprised to see the vacuum drop to 5 inches or so. Why no service people have suggested this is beyond me.

Pushing kerosene or alcohol back thru the lines, presuming there are no check valves, wil help clean them & reduce the vacuum. The downside to cleaning the lines is the potential of removing sludge to the point of creating a leak.

How did I miss this thread when it first appeared??????

 

I would not use compressed air to clear an oil line, especially when you can't see it. Use a push/pull pump instead. I retired my CO2 gun after I split a line years ago.

You said you replaced the lines several years ago. Any chance the ground settled and kinked the lines at the top of the tank?

A Tiger Loop will definirely reduce the running vacuum to almost nothing since the pump will only be moving the equivalent of the burner's firing rate instead of the gearset capacity.