kudos to the pros.

Handi

I have been reading here for some time now. I have even attended several of Dan's seminars - company sponsored :-) . I'm very handy and technically competent. When I installed my W/M P-SGO-4 about 5 years ago i followed the manufct. instructions very close . I did all the work myself ,including the removal of the old dinosaur . I then used a pro to quantify and initial start up .. I maintain my baby regularly . Skim ,blowdown , flue / stack pin & chamber cleaning , oil filter & nozzle changing ect ect .. Since I do not have the full tech expertise or the tools to do a full combustion analyzation, I recently called a pro. I was a bit apprehensive @ first. Reading past posts with regards to questionable service techs. But I must say the tech that showed up was very ,very experienced . He appreciated the fact that I was taking care of the baby and we talked shop while he did his thing .. So this is a positive plug for those excellent and professional oil burner guys out there who know what they are doing and take pride in their work . I do have 2 questions . (1)The tech suggested I install a pressure relief valve on the discharge from the tankless coil , somewhere before it reaches the tempering valve .. ?? this is new to me and although he tried to explain it to me I just did not see how P.R. valve would be required or even how pressure would build up to the point where it might be dangerous .Remember that this is just for the hot water coil .. and not the P.R. valve for the unit , Even I know that is required by code and opens 15 psig.. I have tried to find out more about this on the net but have come up empty. I'm hoping that all the well informed readers here can offer some light to this query ... it would be helpful to know possible brand name , M/N . press. rating and actual installation location .. I can then easily take care of the rest .. A second question is in regard to "short cycling" . Having been reading here for some time I have come to realize that the press. setting @ the pressuretrol should not be more that a pound or two max.. As with most other posts here ,, my pressutrol cannot go that low .. I can get to just shy of 3 psi and about 1 psi diff. the problem is that the unit turns off when it reaches the C/O press. and turn back on @ theC/I . press WAYYY before the stat is satisfied .. this will go on for some time until the stat says "STOP" .. Am I having a venting problem ?? my cast iron baseboard rads are working fine , heating evenly even@ the end away from the boiler .. I hear the air escape fine while press is building up .. but I cant help but think that this cycling is not "normal" .. any theories ?? BDW .. my system is a one pipe with returns at either end of the system and pitch down to a center drop down to the Hartford loop under the pavement and comes up behind the boiler for the return home .. Thanks in advance ,and sorry for the long winded post .

icesailor

53L PR's

The pressure relief valve ( I use a Watts 53L) is a 1/2"  relief for thermal expansion only. In Massachusetts, it is a code requirement on Tankless Heaters. They also require a hot water mixing valve. If you use  a storage tank, that requires a Temperature and pressure relief valve.

As far as your "short Cycling", you're over thinking the problem. It is normal for it to do that. Some here who are better steamers than I will suggest that you lower the pressure. It will work better and I would agree with them.

BobC

What kind of gauge?

The 0-30 gauge that comes with a boiler is not accurate at 2 or 3 PSI. You should check the pressure with a low pressure 0-3 PSI auxiliary gauge so you know what the pressure really is.



How does the boilers sq ft of steam rating compare with the installed EDR of your radiators?  If the boiler is too large maybe you can down fire the oil gun to get closer. Also how long does it take the steam to close your main air vent(s)? You want to vent the header and steam mains fast while venting the radiators more slowly.



My boiler is much to large for the connected load and good venting along with down firing helped reduce the cycling. It still cycles 3-5 times but it's better and pretty efficient now.



Bob