Question about Honeywell T87k thermostat

[Adm]

Greetings,

I just replaced an old H-well round mercury thermostat with a new T87k heat only because the old one's room temp indicator was stuck on 72. I installed the new according to the the directions and set the dip switch to 2 on and left 1 off as indicated in the instructions, but now my heat short cycles.

I have an oil fired hydronic monoflow with cast iron baseboards if that helps... the instructions say dip switch 2 on for "water" heat, is there a different setting to lengthen the heating cycle, or should I just re-install the old one?

TIA for any advice...

 

[Fitter30]

Try off off thats 1 cycle per hour
Off on is 3 cycles per hour

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Honeywell-T87K1007-UserGuide.pdf

 

[Sponsor]

 

[WorthFlorida]

What is your short cycle time? Set the thermostat to 80 or so and time it. The setting OFF-ON is 3 Cycles per hour, OFF-OFF is 5 cycle per hour. IS there an outside temperature sensor?

What is a cycle rate?

What is a cycle rate?

www.honeywellhome.com

Every thermostat has a cycle rate. The purpose of cycle rate is to keep a room's temperature even — never noticeably hot or cold, even though sometimes the equipment is on and sometimes off. Electronic thermostats have a cycle rate adjustment built into them. That's easier, but less fun, than setting the anticipator.

Google "why do thermostat have cycles per hour". Plenty of comments