I recently picked up 6 UPM THM303a thermostats on ebay for our in-floor heating.

(neat little units that also have Humidity readings (and can control a humidifier)..

One of the option settings on them is "System Type", that controls the "Cycles per hour".
Hydronic Heat / Condensing Gas .. 2 cycles
Commercial Unit .. 3 cycles
Gas or Oil Forced Air .. 5 cycles
Electric Heat .. 7 cycles
Also a 'disabled' mode that I assume uses however many cycles per hour is required to maintain +/- 1deg ?

Ive never had a stat with this setting.. other than wear and tear on the zone valves, is there any advantage to various settings ??

 

the smaller the number the longer the run cycle and typically the more comfort. For radiant heat you want a low number.

 

So the stat has to overshoot the temp by some calculated amount.. do these stats 'learn' to some extent ? Nothing said on the package or manual bragging about smarts..

 

I believe that some do... at least as far as the 'anticipator' setting goes. I'm pretty sure that my older Honeywell (with no specific anticipator setting) does 'learn' after a period of time how to set the anticipator for minimum overshoot.

I arrived at this conclusion after observing my old system operation after hooking up the circulator 'post purge' circuit. It did seem to know that more heat would be coming 'after the fact' and always cut off the heat call before the room reached temperature. (which it did always reach temperature with the pump purging the heat from the boiler)

BUT then, neither does this thermostat have a 'cycles per hour' setting.

[ afterthought: It probably DOES have a CPH setting, but it's not apparent, at least they don't call it that and spell it out. I think that almost all digitals DO have a 'system type' setting. This setting probably carries a CPH setting with it but not specifically spelled out in the manual or on the setup screens. ]

 

Honeywell says this about cycle rate:

 

I have no idea if they learn anything. They are not standard thermostats. They are made in Canada, I believe. Contact the manufacturer.

I doubt they overshoot the temp. More likely that the tolerance is tighter.

 

"Again, the actual on and off time of the heating system will vary as the load on the heating system varies."

So the "CPH" is really just an anticipator setting ? Changing the CPH setting really just alters the 'self-heat' function of the anticipator ? The number of cycles is just an example of typical system run periods, but has nothing to do with the actual operation in a given setting.

Now, Im set at the lowest CPH setting (2) .. which should be the least 'heat' for anticipation right ? If Im overshooting temp, then I should increase the CPH setting.

 

I'm afraid I don't have a real answer for you because I don't fully understand the CPH logic myself!

It doesn't make sense to me... I mean, let's say you set it at 2 CPH. Heat call comes and is satisfied, but it is a VERY COLD AND WINDY NIGHT, and 10 minutes after heat call ends, thermostat needs heat again...

Is the thermostat going to sit and wait until a half hour is up before firing the boiler again? That wouldn't be too cool... wait... it would be TOO COOL, maybe even COLD!

I see that you use 'quotes' around the word 'self-heat' and am sure you are using analogy and know that the digital t'stats don't use an actual heating element... that it's all done electronically...

But perhaps your analogy is correct, that the CPH relates somehow to the anticipator setting of old, in a digital sort of way.

I think so... but that's the best answer I can give!

 

Hey guys just thought you might get a kick out of this. I was reading a book about the Brain and Consciousness and the writer making a point said:

Quote:

“My thermostat is conscious. It either thinks it too hot, or too cold, or just right”.

Now I feel next time when one of my thermostats dies I have to have some kind of ceremony.LOL

 

Cremation by Acetylene sounds about right to me... either that, or test the question:

"Will It Blend?"

Consciousness does not imply possession of a soul though. No Soul, No Ceremony!

 

HaHaHa Trooper!

Right again Trooper. I never thought of cremation! And that point about No Soul, No Ceremony will save me some bucks.