Oil Burner not firing...

Well we replaced the circulator and that wasn't the issue. The check valve after the circulator was also working properly. Narrowed it down to some type of blockage in either the stem release or expansion tank. House is warm though with the coal stove so the saga will hold thru the night. Hopefully better luck tomorrow before the Eagles beat the Cards.

As you explained it, I don't see any involvement of the expansion tank. That would cause unexplained high pressures at lower temperatures. I never heard of a stem release.

billlindley wrote:Narrowed it down to some type of blockage

Do you have zone valves? Are they opening properly?

This happens every year to my 1st floor zone when it's in the single digits for more than 24hrs. -- that zone doesn't get used due to the coal stove so it freezes solid. The only way it thaws is if the temp gets up in the 30's for at least a day, & I manually open that zone valve & rap on the pipe with a hammer in all the corners of the house. Once it freezes, it's tough to thaw......unless you have 3 friends with heat guns!

I'll bet the same thing happened here.

Your high limit shouldn't be above 180*-190* . I've found that when I set mine to 200* or above I get MEGA DHW & the rooms heat up quick, but it uses almost 50% more oil! Not worth it IMHO. When my coal stove is off for the season, I set mine at 180* HI with a 10* diff. (most aquastats have no diff adjustment for HI), 150* low with a 10* or 15* diff. Keeps my indirect hot water heater hot & doesn't burn too much oil.

billlindley wrote: Narrowed it down to some type of blockage in either the stem release or expansion tank.

Most likely air bound or frozen pipe, stuck zone valve if applicable.

This is a long shot but what's the pressure reading on the boiler?

What's a "stem release"?

A steam release is probably not the right word. At the top of the expansion tank thier is a valve that will release steam should the system get over loaded. I gave up and called in a friend who knew something about the boiler system. Seems like a frozen pipe now and I can figure where the pipe is but it was very hard to get to. We placed some Heat tape aroudn the pipe last night so I will look to turn it on again tonight.

Fingers are crosses.

I can't imagine an expansion tank releasing steam unless it's filled with hot water and the bladder is broken on an Extrol type tank.

Ok, we finally got to the bottom of this mess. Turns out the check valve went bad and the circulator couldn't push the water thru. We took the check valve off and thru a pass thru piece fo copper on. THe water circulates but now the pump is making a sound that doesn't seem right. It sounds like it lagging or working to hard. If a check valve required in a hydronic heating system after the circulator? Would the water actaully work against the circulator without a check valve in place?

It would be letting the water circulate freely and since warm rises, it would act as a gravity system. You will need to replace the check valve, and thanks for letting us know "the rest of the story". It was frustrating not being able to see or hear the problem. One thought; now that the circulator sounds like it's on the way out. IF you are pumping from the feed side of the boiler, you could replace the circ with a Taco 007 IFC, (Internal Flow Check)or a Taco 00R 3 speed IFC and have the flow check already installed in the pump. Good time to upgrade your system if you have to replace parts anyway. An 1 1/4" check is about 45.00 and a new 00R IFC is 85 ish. A 00R IFC is available as a 3 speed to compete with Grundfos 3 speeds, and usually costs the same as a 00R IFC single speed. I have installed over 60 007 IFC and 00R 3 speeds this winter. Guess what I keep on hand now"! Yes, you can remove the IFC valve if you want to in 15 seconds. Keep us informed. Be safe, stay warm

If you have zone valves, you don't need the check valve. I couldn't find in your posts if you have zone valves.

A check valve? You mean a Flo-Chek like this?


If you bypass that & don't have zone valves, hot water will circulate unchecked with no calls for heat, but shouldn't restrict the flow..........unless the pipe you jammed in there is real small.

The pass thru we replaced it with was the same diameter as the rest of the system (3/4). The circulator we have now is a Taco 007 5F which I don't believe has a internal check valve so I will see if the the local plumbing supply has one in stock. I am going away for 10 days on Wednesday so I just need to get somehting in place that will keep the house warm until my return. The Local Lowes has the Taco the system originally used and what I replaced so if I need to I will just install a new check valve and circulator. The heat woke me up this morning when it kicked on due to the sound of the rushing water. It seems to stop once the temps in the boiler rise I figure the water expands enough to reduce this.


Stoker Man:

There are no zone valves.

Smitty:

The check valve we had looks like this

Thanks again for all the help. It has been a long process.

SMITTY wrote:A check valve? You mean a Flo-Chek like this?

flo_chek.jpg

If you bypass that & don't have zone valves, hot water will circulate unchecked with no calls for heat, but shouldn't restrict the flow..........unless the pipe you jammed in there is real small.

Those valves should have a drip leg (a 3-4" nipple with a pipe cap) on the bottom port to allow sediment to settle out of the valve, otherwise they tend to bind up from it.

Perhaps that the reason it got stuck and restricted flow. I will look into the one you suggested. Hopefully it will be the same length so it won't be a pain to install.

The Taco 007 has NO check valve