Annually recurring Riello F3 issue

EBEBRATT-Ed

Yeah, @Charlie from wmass & @STEVEusaPA are correct the damper shouldn't be in a tee and certainly on on the run of the tee.

Your installer needs to read .........read the instructions packed with any damper

Brent H.

@Charlie from wmass

The latest manual on the Fields website doesn’t even talk about using a tee. I did find an older manual on the SupplyHouse.com site that mentions the maximum distance when installed on a tee.

STEVEusaPA

It has never been allowed on the run of a tee for oil.

EBEBRATT-Ed

@Brent H.

For gas the barometric can be installed on the run of a tee as yours is but it must be a double acting control with a spill switch wire to shut the burner down.

For oil the damper must be installed on a branch. I have seen many installed on the branch of a tee, Field does not like this. Installers are too lazy to cut the smoke pipe and install the collar so they use a tee. Not right.

A tee with the control on the branch does not allow the barometric to open into the pipe properly, that's why they want it in the collar

Brent H.

@EBEBRATT-Ed

Thanks for the info. I had fired off an email last night to Field Controls as I wanted something in writing to bring to my installer. I received a response this morning. As you have all said, installation into a bullhead tee is not an authorized method. They did however state that installation into the branch of a tee is acceptable as long as the branch protrudes a minimum of 2.5” ( for the 5” draft control) to allow proper operation.

I’m sure they installed it where they did because it was easy...... cutting 24 gauge pipe is not fun as I experienced last weekend when I installed it.

Thanks.

STEVEusaPA

24 gauge is easy to cut with snips...do it all the time. Or you use the supplied collar and cut it into the straight pipe as instructed.

Ctoilman

I agree the damper is not in the correct location according to the manufacturers instructions.  How it's installed reduces chimney draft over the boiler a lot, but in your case still not enough.  The concern is that when the damper is full open could the flue gases be potentially diverted into the living space?  In other words, does the damper plate protrude into the pipe when wide open? 
Has anyone installed the cast iron damper plates Buderus supplies in order to establish proper overfire draft?  They're inside the boiler btw.  
You need a qualified burner tech to fix the problem(s).  I'd get Buderus involved if need be.

EBEBRATT-Ed

Cutting 24 gauge with tin snips make me bleed just thinking about it. I really like my $100 electric nibblers about 30 years old and they save a lot of band aids

Actually cutting with snips is ok. It's snapping 3,4 and 5" 24 gauge together that gives me a problem

Charlie from wmass

EBEBRATT-Ed said:

Cutting 24 gauge with tin snips make me bleed just thinking about it. I really like my $100 electric nibblers about 30 years old and they save a lot of band aids Actually cutting with snips is ok. It's snapping 3,4 and 5" 24 gauge together that gives me a problem

3,4,5 only n|ds to be 26 gauge. I can't even find 24 gauge in those sizes most places or I would use it. But tin always means blood is drawn. Lol 

Brent H.

The service tech. is coming back tomorrow to move the location of the draft control. My preference would be to move the tee so it starts after the first section of straight pipe. This will keep it 2’ from the first 90 coming off the boiler but still a couple pipe diameters before the 90 that goes into the stainless chimney snout. Only issue with this location is that there will only be 2.5” - 3” between the face of the draft control and a lolly column and galvanized air intake. Any concerns with this?

Thanks.

EBEBRATT-Ed

As long as there is room enough for the control to swing it will be ok.

I would replace the tee with a 90 instead of capping the tee....better draft

STEVEusaPA

Ditch the tee, use a 90, and use the draft collar that came in the box with the draft regulator.

Brent H.

Many thanks to all of your for your help and advice over the last couple months. They came today and moved the draft control to the spot I requested and put a 90 where the tee had been. Talking to the tech, I don't think he believes anything was wrong with where they put it because they do it all the time😀I suggested the manufacturer probably knows best and the documentation specifically shows not to install it how they did. I’m hopeful with the draft control and the Riello set to the newer specs. it will run for the next year without issue.

One follow up out of curiousity.... talking to the tech he said they don’t install many with SS chimney liners. In what cases is a SS liner needed? I have a 25 year old chimney with normal 8x8 flue tile but wasn’t given the option of not having a liner when the boiler was installed 10 years ago.

Thanks again.

EBEBRATT-Ed

They make liners in aluminum & stainless. Obviously stainless is more $$$$ but holds up a lot better and is the best choice unless your selling the house.

Basically, the newer boilers are designed to run at lower stack temps.......that's the key to better efficiency.

A boiler with awful combustion will come out with decent efficiency if the stack temp is low enough.

Because the new boiler runs at lower stack temps a masonary chimney will not heat up fast enough and may cause condensation which will deteriorate the chimney and may cause poor draft.

A stainless or aluminum liner is thin and has less mass and will heat up very quickly and give better draft and any condensate is less likely to harm it.

What is easier to heat up a liner or a pile of brick, clay liner and mortar?

Did they combustion test your boiler??

Brent H.

@EBEBRATT-Ed

Thanks for the info on liners. Is there any code requiring installation?

Yes, they did combustion test with an analyzer and then wrote it on an old school ticket instead of leaving a printout.

HVACNUT

A 275° net stack temp means they didn't run the boiler to steady state before testing, or something is seriously wrong. Or both.

EBEBRATT-Ed

Yeah stack temp is low.

Liner jnstalation is always required if the chimney is suspect. Otherwise it depends on the size of the chimney , height of chimney,flue, the BTU input of the appliance, weather it is an inside or outside chimney and climate location (how cold it gets in your area) etc, etc etc

Ctoilman

275 net stack is fine with a puny .55 nozzle.  I don't like a nozzle size less than .60....but it is what it is.

STEVEusaPA

Stack temperature has more to do with draft and excess air vs. nozzle size. For oil you shouldn't be below net 300° and you definitely need a SS liner, unless you are doing power burner or balanced flue.

EBEBRATT-Ed

I don't see the size of the firing rate between a small boiler and a large boiler affecting stack temp. If they are fired correctly they should have about the same stack temp

Brent H.

The latest Riello specs call for .55 x 60 nozzle with 185 psi.

I looked back at previous combustion tests and net stack temp. prior to new liner and draft control was 250 but that was measured a while ago. I just need one of you to work in Central MA😀