Question about installing 24 volt thermostat

Mike Cascio

Hi,

I have a weil-mclain Eg boiler currently being controlled with a honeywell T87 round thermostat. With the current wiring set up the way it is, will a thermostat with a clock that runs on 24 vac work?

Thank you,
Michael J. Cascio

Robert O'Connor_12

24 volt t-stat

It depends on which thermostat it is. Depending on which one you get, try an match the amperage draw of the gas valve to the anticipator setting on the t-stat, this will give you a more even cycle and you will not overshoot or undershoot your set point.

Robert O'Connor/NJ

soot_seeker_2

sure - why not? - addtl note about t-stats & dst -

sure - why not?

most newer thermostats with a digital clock actually run the internal single pole relay off the batteries not the 24vac. the backup coin cell battery (if present) is usually just for the clock. some have the capability to 'steal' power from the 24vac xfrmr but this is usually not the default wiring.

also, just a note about recent thermostat products on the current market.....

if you have perused ebay & some big box store outlets over the last year or so you may have noticed some very nice pricier type t-stats from many companies being almost 'dumped' out at very low pricing. ever wonder why? well, the t-stat manufacturers learned way before we did recently that the daylight savings time 'dates' were going to be altered for the first time in decades. most of these t-stats just had a setting for daylight savings time on/off - already burned into the firmware - already manufactured - in the warehouses - and in the stores - with no capability to change the old date settings in the future (like the newer ones coming out now). so, guess what happens when your name is honeywell & one of your pricier features - named on the box - is the ability to handle daylight savings time. well, get rid of them - cheap - before the legislation passes.

by the way, this goes for all your vcr, etc. products - as well as the windows 95, 98 o/s etc., - and your watch, and so on, and so on....... you get the picture.........

ss

soot_seeker_2

anticipation - not an issue on a newer digital t-stat..

assuming a newer digital thermostat - they don't care about anticipation via current loop resistance - that's an old mechanical t-stat item where the resistor had to fool the bimetalic switch. that hysteresis effect is now handled internally by firmware and the aggressiveness of even that function can usually be further adjusted in the installer setup.

ss

Mike Cascio

This is an old honeywell chronotherm II thermostat with a manual clock, I am just interested in night set back. Will this thermostat work?

Thank you,
Michael J. Cascio

soot_seeker_2

yup..

that's an ugly t-stat - but yes.

why not blow $29. & get something with a really accurate temp sensor, multiple set-backs, adaptive recovery, random & blower delay settings for increased fan & system efficiencies, and a clock that you don't have to reset when the power goes off, etc.

i would think it would pay for itself in a year and provide better comfort as well. no?

ss

Glenn Harrison_2

Michael,

Just to be sure I would go to the website below, and where it says "Literature Resources", enter the model number of your t-stat to find any manuals on your particular model. TYhen you should know if i will work or not. If my memory serves me, some of the Chronotherm II's required a common wire to power the clock, some required a separate power source, and some would just power steal beteewn R and W when there was no call for heat.