vaillant boiler comb chamber

billygoat22

had a very sooted up boiler last week. after nearly 3 hrs working on it got running again.

Just inside the burner door was a pc refractory material that was once shaped like an 8" long pc of 8x8 flue tile, lying on its side. no evidence of the dish piece that many of these Vaillants have at back end inside. I have never seen one with this part and would like to find some info.

It may be some of the previous ones lacked this part as well. Last one had difficult time to get to clean up flame, and now I wonder if that one had the same issue. This on pulled the pieces out and its running 9% CO2, trying to get the yellow out smoke test, then finish up by resetting combustion. But w/o combchamber, I suspect no hope of getting the performance up where it needs to be.

Can get some parts, but I have no diagrams to check and see if parts are right. and the parts are non-returnable. thanks for any insight you can give. I figure there's a lot more of these in NE part of US and some guys have been around long enough to see when the boilers were newer and manuf was still in country.

Steamhead

What model Vaillant?

billygoat22

F70-W-70PP. Sorry 'bout that.

Has a Carlin burner, 99FRD. did get a manual on that, and Carlin recommended a 1.35 60A nozzle @ 150#. I guessed when there w/a 1.35 60B @ 140#.

Steamhead

Well, now we know why it sooted up. A solid nozzle where a hollow is supposed to be will do that every time. You can't fix stupid.

Lynn makes a chamber kit for those, # 1117. You can get them from R.E. Michel or Sid Harvey. This is the most recent design.

The vertical passages between the firebox and the flue collector area are supposed to have baffles in them. Many times these are missing, resulting in high stack temperatures and high fuel consumption. You can get replacements from Parts To Your Door, here:

https://www.partstoyourdoor.com/p/2652/flue-turbulators-f70

This company also sells Vaillant chamber kits, in case you have trouble getting the Lynn kit.

billygoat22

Boiler was sooted before I came along. Had a .85xxx nozzle in it, likely a combination of comb chamber bad, nozzle and poor maintenance.

Every one of the Vaillants I've seen 1st time out had to dismantle and clean. I tell owner they have secret passages since every one looks like never cleaned.
one looked like had cement in vertical passages, and was in crawlspace w/only 16" above top of it. Can't image dragging something like that 20' into a crawl.

billygoat22

thanks, steamhead

billtwocase

Only came across these with AFG. Was this a replacement burner? Early Carlin ran best with Hago semisolid. 98 Miser, 99 FRD burners were poor. This boiler would be best with a AFG, or NX

billygoat22

From what I've found, these models are 20 yr old minimum. Customer was looking to try to get running vs replacement. For age of boiler, unlikely would buy new burner, especially w/parts getting harder to find.

Have had one cust replace burner on a burnham boiler, 50-60s vintage. She must have really liked it. Even w/o refractory, (never had it) burner still gets better efficiency than old burner did.

Steamhead

That's typical when replacing an old-style burner with a flame-retention one. 10% savings is minimum.

The Vaillant was one of the first Euro-boilers sold here and a lot of guys didn't understand them, so we find a lot that were knuckleheaded. They needed a burner that could develop some static air pressure- the Beckett AFG was minimum, the AF-2 was better. Carlin had an OEM spec for these too (most recent was the EZ-66) but I've never seen one in the field. They run fine with the proper baffles and chamber kit and with the burner properly tuned. We have one running nicely with a Carlin EZ-Gas too.

billygoat22

Went back today for no heat, afraid would be sooted again, but the ignition transformer had died. replaced the nozzle w/spec one by Carlin, and trace to 1 smoke on it still.
Local REM cannot get description on part, so don't know if right part or no. Looked at Sid Harvey site, and no pics there, either.

Given the difficulty of parts availability, age and the burner starting to act up, recommended to replace it. Customer said was nearly 40 yrs old.

billygoat22

The one speced by REM is supposed to be new old stock.

Steamhead

billygoat22 said:

Went back today for no heat, afraid would be sooted again, but the ignition transformer had died. replaced the nozzle w/spec one by Carlin, and trace to 1 smoke on it still.
Local REM cannot get description on part, so don't know if right part or no. Looked at Sid Harvey site, and no pics there, either.

Given the difficulty of parts availability, age and the burner starting to act up, recommended to replace it. Customer said was nearly 40 yrs old.

And they wonder why we drink...................

REM catalog# is 2M895L. I've gotten a couple of these- it is the right part. You can expect some smoke without the proper chamber. There also may still be some soot burning out of it.

billygoat22

all right, thanks. I'd be excited to get the thing running like new again.

billtwocase

You can also get that from Lynn Manufacturing part# 1117