Dealing with suspended condensate in an oversized boiler.

BrianStMarie

This past spring, I converted my Burham V83 from oil to gas burner (Carlin EZ-Gas). Before the conversion, the old Beckett burner was firing at 0.6, or 84k BTU/hr. After the conversion, the burner is supposedly firing around 90k according to the tech, though I have serious doubts.



Prior to conversion, it took about 15-20 minutes before the radiators would start to get hot and a total of 45 minutes run time before all the vents were closed and the radiators were completely hot. The system would start cycling on pressure at a little over an hour of continuous run-time when recovering from a set back.



Post conversion, the radiators start to get hot in less than 10 minutes, are totally hot and vents closed by 20 minutes and the system cycles on pressure by about 30 minutes. This is really fast. And the biggest problem is that once the vents start closing, the steam pounds the condensate back into the remaining radiators, causing an intense boiling/bubbling noise. The last radiator vent to close is usually spitting condensate before it finally closes. This is not good.



So, first question, is there any chance in hell that this is actually running at 90k when it was running at 84k before and taking twice the time? I have a feeling I'm running at more like 150k or something ridiculous, which is out of spec for this boiler.



Next question, is there anything I can do other than downfiring to slow the steam down and keep it from roughing up the condensate so much toward the end of the cycle? I'm fairly sure this is going to trash my vents and I'll end up needing to replace them all.



Thanks.

nicholas bonham-carter

spitting vents

what sort of radiator and main vents have you? some vents are notorious at spitting, especially if the main venting is inadequate.

what is your pressure on the gauge. it should be less than 1.5 psi for basic function, or a couple of ounces for economy and comfort.

do a search here for clocking the gas meter to find out what your burner is firing at.

post a picture of your boiler supply piping so we can see if that may be a contributing factor.--nbc

are the pipes insulated?

Dave in QCA

Everything nbc said, plus this....

If it is a new boiler, was it properly skimmed and cleaned?  Many times, a dirty boiler, (and all new boilers are oily and dirty) will cause foaming and throw water up into the mains.  This will cause all kinds of problems and can cause symptoms exactly as you describe.