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short cycles, low diffs, oh my!
please pardon the tone. i am angry with the state of manufacture of this equipment. seemingly the things i am allowed to adjust on the system are not allowing me to have desired effect.
i have an oil fire 2-zone boiler with domestic coil. it is a crown shorty something. whenever it turns on the flue runs it seems like a big process to start the fire... loud flue fan starts for a few secs then you hear the roar of the flame below. outside, you can smell the aerosoled oil that is certainly not getting burned each time a start up cycle occurs.
i'd like to stop throwing money out of the window. i want it to turn on once an hour maximum. even on cold days. and stay running until call for heat is exhausted. not on and off several times an hour.
currently with both zones running it can start at its cold low limit of 160 and run to my programmed high limit 205 in about 10 mins. a decent cycle, though ideally it wouldn't stop during the call for heat. i don't understand why the fuel pump inside can't just back off a little once it gets up to max temp and stay there but whatever. fixed nozzles and things i'm sure. (2018, we can land on moon but wow home heating fixed temp)
the truly baffling thing is that my honeywell L7224u has but a 10 degree differential. so once the boiler hits high limit, it shuts off a good 2 mins before turning on again. you know, kerosene out the window... etc. (boiler temp bounces 195-205).
sometimes the thermostats are out of sync, the bottom zone will call for heat --and this whole process happens much faster. This is infuriating knowing all the thermal cycles going on, probably the (extra) soot formation and localized heating among other bad effects when the machine turns on and off this often. let alone any spurious domestic water demands.
why are these systems designed like this? 10 degree differential? surely this is a bad joke played on me by the installer!
i noticed if i want "heat scavenging feature" --aka normal operation for me not a "green feature" -- i must pay $ or so for a new aquastat board from the incompetents at honeywell. how is this a thing!?
are there other levers i can pull on this machine or do i have to deal with some idiotic board from honeywell designed in 1980 with ridiculous hard-programmed differentials? are there alternatives to running this boiler as intended?
please help me understand... i've read of folks putting relays so the circulators run separate from the boiler and can "scavenge" the heat (once again, this should be normal operation not extra feature) is this what i must resort to?