Best Of
Re: Best way to handle short cycling on boiler
I would look at the system a little more. How does the system heat? How long to get heat to the radiation from a cold start (boiler warm pipes basement temp).
We need to find out if the system has adequate venting. Lack of venting can cause short cycling even if the boiler is the correct size.
Re: Adding thermal purge to oil boiler with 2 zones
what is the goal of the purge? How high of a mass do you have to make it worthwhile to purge? Will the purge overheat a zone or room?
The purge may leave you with a cold start boiler on every fire? Cold starts are the least efficient run mode for that boiler, so any purge gains may go up the flue anyways.
I’d be looking for a way to keep the boiler online as much and long as possible. Outdoor reset is a good option for long or near constant boiler run cycles.
hot_rod
Re: Any issues with long pigtail for pressuretrol
@melo, there is no issue with the pigtail in your picture.
Re: Flue liners hindering check of flue
Pull the cap off and shine a decent flash light down it while looking up with the mirror?
ChrisJ
Re: Does any company make slip tees in propress/copper press standard?
I know on most sweat copper couplings or tees you can file out the stop and slide it up the tube.
I don’t think the hub design of typical press fitting allows that?
hot_rod
Re: Adding thermal purge to oil boiler with 2 zones
What type of boiler? If a standard gas or oil fired, there are aquastats that offer zone purging. If a mod con boiler, maybe there's something in the setup.
HVACNUT
Re: Advice for replacing a Bell & Gossett 2-1/2" with a Grundfos
You could try replacing the steel pipe clamps on the piping with "cushy clamps".
They have a rubber inserts for vibration and allow expansion.
JUGHNE
Re: Best way to handle short cycling on boiler
I would not replace it either.
A few things IMO;
I wonder about the boiler's wiring, with the damper cycling like that. Commonly the thermostat controls the damper, the damper when fully open (via the dampers 'End Switch') controls the burner. The pressuretrol is electrically often on the burner side of the damper.
What make and model boiler do you have ?
If it were my oversized boiler (one method) I would add a delay timer, so once the pressuretrol trips on pressure (system pretty much full of steam) the burner restart is delayed (in minutes) beyond the point of the pressure drop and the pressuretrol resets. To me burning fuel just to build pressure is a waste and needlessly cycling the equipment is also a waste.
Another method is Duty Cycle or PWM (Pulse Width Modulation) control of the burner beyond the obvious Duty Cycle control of the thermostat. Adding a temperature sensor can enhance this method. With this method the burner never runs long enough to build significant pressure.
The difficulty with the timer method (as least the way I see it) there is not a perfect delay timer that is easy to install and works as desired on most any system. And it seems most folks are not really good with electrical stuff in general.
109A_5
Re: Troubleshooting No Ignition
Geez a guy makes one stray comment. All right, I’ll follow the current.
nickr
Re: Adding thermal purge to oil boiler with 2 zones
I use a delay off timer to purge my boiler, while the zone calls it goes thru the timer and then after the zone call is ended the timer maintains power to the pump. My pump is in series with an inline open on temp rise aquastat so once the temp is below setpoint it stops purging.
