Frequent Boiler Cycling
I recently replaced the old programable thermostat on my steam system with a new Honeywell digital thermostat. Since then the boiler has been cycling much more frequently. There was a reference in the instructions to heating cycles, but the minimum setting (indicated for steam) appears to be twice an hour. Is this the wrong thermostat…
I recently replaced the old programable thermostat on my steam system with a new Honeywell digital thermostat. Since then the boiler has been cycling much more frequently. There was a reference in the instructions to heating cycles, but the minimum setting (indicated for steam) appears to be twice an hour. Is this the wrong thermostat for the system? Is there anyway to get it to cycle less frequently – I assume that the frequent cycling is wasting fuel.
The new thermostat is trying to minimize temperature swing. That’s the amount the temperature rises above the room setting and how much it drops below before it turns on again.
The role of the pressure rise is an internal function of the boiler and the system and has little connection with thermostat settings.
In other words, don’t let it drive you crazy.
Thanks for the feedback, but I’m still confused. The minimum cycle setting is “2=30 minutes” according to the user guide (Honeywell RTH230B). Does this mean that the boiler will only fire up twice an hour max? The radiators seem to be heating up adequately, in fact I have lowered the temperature by a degree as the house seems warmer than it used to be. I am unclear about the role of the pressure rise…no problems prior to installing new thermostat, but boiler appeared to run longer/less frequently.
Then again, I spelled plumbing wrong.
That’s because ALL thermostats are set to work with forced air. Only about 15 percent of the country, mostly in the Northeast, uses water-based heating systems.
Steam heating systems generally work at 2-3 cycles per hour, but as Slopefarm suggested, a single cycle may include more than one off/on events due to pressure rise.
Me:
http://www.GatewayPluming.com
Honeywell digital thermostat by default are set to 6 cph. If you have a steam system, change it to 1cph.
Is it cycling from the thermostat or from pressure? That is, is it the thermostat that keeps calling for heat and then shutting it off, or does the cycling occur at the boiler all while the heat has not reached the temperature called for by the thermostat? Watch it closely, then call a plumber.