crown ctpb 35 oif fired boiler problems

peats

i installed this boiler in 2003 and have only been able to get through 2 seasons without it going down, always with a sooted up turbulater. have used 3 different service companies with no different results. using the spected nozzle and a fresh air kit. it has a field power vent with a total of 5' of flue. no soot shows outside. cant seem to tune this burner to get through 100 gallons of fuel without going down. anybody have any ideas? my service company is at a loos as what to do to fix this issue,

Steamhead

What burner is on this boiler?

What are the combustion test results?

Where are you located? How cold does it get there?

peats

beckett burner, not cold, located in eastern PA. was cleaned and serviced in september. tune lasted 75 days and shut down. service came back, went over everything. boiler went down again 30 days later. don't have test results but service company assures it is tuned to spec. burner went down 3 times last year on 600 gallons of fuel and every year it is the same thing. this is a cold start boiler for infloor heat.

lchmb

I would be looking at the drawer assembly for a crack or maybe check the cutoff on the pump to start...

STEVEusaPA

Cold start, but power vented w/fresh air. Black soot or brown soot?
Usually sooted up turbulator (to me) means lack of air. The combustion numbers are key. Could be lack of air because it's set up in the summer (warm air) and now it's pulling in cold air.
When you say it 'went down', exactly what happened-I assume the primary locked out?
It really could be anything from a loose wire, pressure switch on PV, dead spot on motor, failing (annoying) ignition transformer, or something with the pump. None of that helps you today because that means 'anything'.
When the primary locks out, you can get some clues when reset and it fires that could point you toward ignitor or motor. But these components can be tested with a meter.
Maybe it's just too much draft and the flame is being pulled off the end cone.
Being that you bring in combustion air, how long is the pipe from exterior to burner?
Also, is anything (the same thing) going on weather-wise when it goes down, and similarities-i.e. like today in our area were getting a noreaster. So strong wind either hitting the PV or hitting the combustion air intake. You could watch the effects of this by monitoring the cad cell.


2 trouble shooting options:
1. Put a new Carlin primary control on. It has some nice built in diagnostics that may point you in the right direction.
2. Old school-bring out the beast! I still have my OnWatch kit that hooks to every component on the system and data logs. This will at least tell you if it is failing on start up, mid cycle, or something going on during shutdown.
I've used it about 4 times now in all the years I've owned it. It's perfect for these types of situations, however it's a PITA to set up, and technology wise, it's really outdated to the point that I keep an old laptop (Windows XP) dedicated just for it.

billtwocase

What is the post purge timing on the power vent? Is there a fan prover wired in? Does it have a spillage switch? Wired thru B-1, or orange from cad cell relay? Breech and over fire draft readings? Etc, etc, etc. So many possibilities. Too bad so far away. I love challenges

peats

about 2 minutes on post purge. most of the other stuff is greek to me.master plumber with 44 years in the field, but heating is a totally different field. have not found a tech in the area to figure it out. was using a company that would do the tune, but when it would fail, he would scrape off the retention head, hit the switch, and send me the bill!! i clean it myself now but the issue seems to be getting worse. thinking the oil pump cutoff as suggested.when it burns it burns well. that excess oil has to be coming from somewhere. the other problem is when an adjustment is made, it takes 1,2, or 3 months to decide if there is improvement.

peats

fresh air intake is about 15' metal pipe. i added it on the suggestion of a tech that thought the house might be too tight. had problems before and after the air intake was installed. no real change. brown soot,always the same problem and always the same fix. clean off the retention head with an old toothbrush, give it a shot of brake clean, reinstall the assembly and hit the switch.

billtwocase

Find a better tech. Replace the electrodes, boost the pump pressure, if not already at 140, if AFG, check you "Z" setting to start

STEVEusaPA

See now brown to me would be too much air being pulled thru the unit.
Do you combustion test results, specifically draft, over the fire and over the breech.

Steamhead

I'd bet the power venter is pulling too much draft.

Where in Eastern PA are you?

peats

i'm in emmaus, outside of allentown. pump pressure is 140. not sure exactly what tests the service man is doing. The Oil Man (torn pants around his **** and a disheveled look), but again this is the 3rd company with the same results.

Steamhead

@STEVEusaPA , is that too far away for you?

peats

there is a damper on the air boot, how would i adjust the power venter? there is also a damper on the flue before the power venter.

Steamhead

You need the right tech with the right equipment to make these adjustments. It's not a DIY job.

Also- I haven't located the manual for this boiler yet, but on this page:

https://www.johnstonesupply.com/storefront/product-view.ep?pID=L97-263

it says the burner runs with positive pressure. That means the pressure in the firing zone is supposed to be slightly above atmospheric. So, if the power venter is overdoing its job, the flame could be pulling off the burner head (called "loss of retention") instead of burning in a stable manner. I've only had this happen once, on a burner I did not install, and it can take a while to figure out.

This is why we need to see the combustion test results. If they're way off, this might indicate a loss of retention. If no one did a combustion test, that's a BIG part of your problem.

If you have the boiler manual, can you post the burner setup specifications?

peats

your comments are very helpful and i am not going to try to fix this thing myself, however i am going to take all of this input and present it to the best tech i can find in my area and finally get this thing resolved. i thank every one for their comments and input.

peats

i don't think i have the manual but i will get it and post that info. i think that your theory of negative pressure is very possible. i am optomistic that i can get this thing fixed. one thing that i didn't mention is that i replaced the power venter motor last year and maybe the new motor is pulling even more than the worn out one, shortening the time between failure. just a thought.

billtwocase

Just the motor, or the whole housing? The baffle should be set for recommended drafts. How was the fan proving tube? That would be visible when you remove the motor assembly

STEVEusaPA

Steamhead said:

@STEVEusaPA , is that too far away for you?

Thanks Frank. It's a good 1 1/2 each way, no traffic. I'm down in Delaware County, next to Philly Airport.
I think we're on to the right path with the power venter.
Here's the manual
http://www.velocityboilerworks.com/documents/Freeport-CT-Installation-Manual.pdf
According to the manual, -.02 at the breech. Also there is a special note about power venters

billtwocase

Just a heads up to the poster, the damper you refer to on the air boot is a vacuum relief. It only needs to open if the hood is blocked outside. It doesn't contribute to your problem. If they can not get the correct breech and over fire draft, the baffle needs to be adjusted just after the transition where the pipe enters the venter. Loosen the 1/4" screw, and rotate to adjust. Only has a 1/4 throw. If you could get Steve or Frank there, you would be golden

peats

just changed the motor and fan cage. just remembered i had some issues with the proving tube clogging up early on but have not dealt with that issue for years.such a wealth of knowledge, you guys have been great