New boiler woes

ottawamerc

Hi guys

I installed a new steam boiler in a 3 storie 12 unit apartment this past summer. I replaced an old sectional oil fired boiler with a new Slantfin Caravan modular gas fired boiler. The old unit was 700,000 BTU and the new system is a total of 900,00btu. I'm having a few issues I would like to try to find out the causes to. First as the boilers are making steam the water levels drop in the boiler but seem to raise in the equalizer header so the condensate pump wont run, then the boilers will go off on the low water controls mounted on each module. At that point the water level drops in the equalizer header and the pump will start? I have the header installed as per the manufactures manual and the #46 pump control at the correct level. I have the equalizer header and all three condensate return pipes at the same level as the return tappings on the boiler which is ok in the manual but it shows in the schematic that the condensate pipes go down to the ground then to the equalizer header? I'm thinking that since the piping is horizontal that maybe there is not enough head pressure and the steam is forcing the water back up the equalizer. I talked to the Slantfin tech line and they thought the piping was ok and the boiler needed to be skimmed, I have tried that several times but still the same issue. I'm kinda at a loss here now?

Second issue is some rads are not getting any steam now either. When I first fired the system in the fall all the risers worked fine but lately some are not heating up. It is a one pipe system with steam traps on the bottom of the risers and air vents on the rads. I have read on here that there should be vents on the mains as well but I have not seen any yet could that be the issue?

Sorry for the long post and I will post pics soon

Abracadabra

ottawamerc said:

Hi guys

The old unit was 700,000 BTU and the new system is a total of 900,00btu.

Is the boiler oversized now? What's the attached EDR?

vaporvac

Could you please post some pics of the near boiler piping?

Abracadabra said:

ottawamerc said:

Hi guys

The old unit was 700,000 BTU and the new system is a total of 900,00btu.

Is the boiler oversized now? What's the attached EDR?

What is the attached edr, how many boilers and which ratings? I have two new TR50s caravanned and a few people who visit this site are adept at troubleshooting them. It sounds like you need more skimming. I've done mine numerous times and they still need more as I had a lot of new piping, plus the oil from the boilers themselves.

Lack of adequate venting and sags in piping can often lead to cold rads. Is there any banging? If yes, at what point in the cycle does it happen.

How are these staged, btw?

ottawamerc

There is no banging in the system and no sags that are visible anyways. As for staging I have the pressure trolls on the 3 boilers set a 1/4# increments but the boilers never run long enough to make any noticeable pressure before the thermostat is satisfied. Should I completely drain the system and add fresh water?

ottawamerc

A couple of pics of the install

ottawamerc

Another

vaporvac

OK. I see no one else has answered. I may be jumping to the wrong conclusion, but when you ask, "Should I completely drain the system and add fresh water?", it makes me think that's what you did for skimming. That won't work as the oils just line the inside of the boilers and float to the top when you refill. I believe that model has a very cool skimming feature built-in. How did you skim it? Did you bring it to 7lb. pressure?
I have experienced the exact same thing and it went away after I skimmed, although Ineeded (and still need) to repeat it, as there's alot of oil in two boilers and their associated piping. I do not have a feed pump or even a reservoir tank. SF suggested waiting to see if i needed one andso far, so good. So I can't really comment on the feed pump issue. I really cleaned out my wet returns, however.

You never gave your edr or an explanation of why you increased the BTS so substantially. Are these staged or do they all come on at once?

There should be some venting on the system, either on the returns or mains, but who knows what happens over the years. Can you find a place where it looks like a vent was removed, although if you're not making much pressure that may not be the issue. More likely some traps have failed.

ottawamerc

Thanks for the reply I did use the skimmer on the side of the boiler multiple times and I have not drained the complete system yet anyways. Could the oily debris be in the pump control float causing the issue too?

Thanks