Peerless pf-80 boiler short cycles

[Lee H]

Boiler when first installed modulated output to maintain approx 180f, but did not cycle off. Requested installer increase temp for more heat. Now boiler goes to about 185, shuts off, purges and waits to restart. I adjusted reset curve design to default 180 from 189 and reset curve to default 195 from 189. CH mode is 1, thermostat and outdoor reset. Some improvement noted, but boiler still cycles. Is there possibly a hidden menu with an overall water temp limit that is causing burner to cycle off?

 

[Lee H]

Anybody there?

 

[Sponsor]

 

[Dana]

According to the manual the PF 80 is built with hard safety limit switches that trip whenever it hits 210F. Those are not high precision controls, and 210F is the maximum temperature at which it can trip and still meet the ASME certification requirements.

It's conceivable you're flying a bit too close to the sun there and tripping the safety limits, which is possible if the flow through the boiler is on the low side.

Almost no heating systems NEED to be operated at such a high temperature to keep the place warm, even during cold snaps more than 10F cooler than the 99% outside design temperatures. Are you cranking it up that high in order to use overnight setbacks or something?