Looking For a Decent 24 Volt Thermostat

[Winmon]

I am looking to get a decent new 24 volt thermostat for my Bigg Maxx heater. The one I got from Northern (only had 1 choice) is a piece of ****.

Anyone have any recommendations and a online source for them?

 

[MyDomain]

Your best bet would be a simple Honeywell T87F thermostat available at any home store or hardware. Here on eBay http://cgi.ebay.com/Honeywell-Therm...ryZ41988QQssPageNameZWDVWQQrdZ1QQcmdZViewItem.

If you want to use a digital tstat Mr heater recommends using an isolation relay along with it. Otherwise the spark ignition may mess with the logic circuit in the digital stat. With an isolation relay the tstat closes contacts on the relay, another set of contacts then close on the relay and starts the heater.
Let me know if you have other questions.
Tim

 

[Winmon]

Thanks Tim. Any idea what isolation relay I need and where I can buy it?

 

[JohnZ]

My Reznor is on an ordinary White-Rodgers residential furnace thermostat (well out of the way and around a corner from the airflow), and all of those have a 2* set-point drop. I want one with (or that I can set at) a 10* set-point drop, so it'll run to 75*, shut off, and not cycle again until it drops to 65* (so it doesn't keep short-cycling). Can't find one anywhere like that - anyone have a clue where I might find one?

 

[MyDomain]

Thanks Tim. Any idea what isolation relay I need and where I can buy it?

You will need a seperate 110 vac primary, 24vac secondary transformer. Then get a spdt relay with a 24 vac coil. The thermostat is a switch that will make or break the 24v coming from the transformer to the coil terminals of the 24v relay. In other words you have a hot and a common from the transformer going to the relay. You insert the thermostat in series with the hot wire to the relay, R to the transformer and W to the relay.

Now, you take two wires off of the N/O terminal and common on the relay and run them to the tstat terminals on the heater (R and W).

If you want to be able to run the fan (G terminal) without the heat then you will need a DPDT tstat. You should be able to run R off the tstat to the transformer hot and W and G to the coil on the relay. Then run the wires for the fan to G on the heater off of the other N/O contact on the relay.

You can get a relay like this from any HVAC supply house (that will sell to you), maybe a home supply store or ask a HVAC company to get it for you. If what I said made sense you can do the work yourself. I can try to help more but it is hard sight unseen. If it lost you you may want to get an HVAC tech to do it for you.

 

[MyDomain]

My Reznor is on an ordinary White-Rodgers residential furnace thermostat (well out of the way and around a corner from the airflow), and all of those have a 2* set-point drop. I want one with (or that I can set at) a 10* set-point drop, so it'll run to 75*, shut off, and not cycle again until it drops to 65* (so it doesn't keep short-cycling). Can't find one anywhere like that - anyone have a clue where I might find one?

Most better digital stats have the capability to adjust cycle rates in their set-up menu. Look in the instructions for it. IMHO as a pro, a 2 degree drop is not short cycling rather normal. Most people can feel a 2 degree drop and start to get uncomfortable when the temps swing more. IMHO it is a waste of fuel as well. If you need a manual for your stat just let me know. And let me know if I can help you any further or if my understanding of your question is way off base!
Tim

 

[Winmon]

Thanks Tim ! A little too involved. Think I will just go with a simple Honeywell CT87 series analog....

 

[MyDomain]

Sorry friend...it's not really that hard, just sounds bad to someone that doesn't do it much. There is a combo unit that is $200 and would handle the heating part without a lot of custom wiring. Not the constant fan though.

If you were my neighbor I would hook you up, Washington is a bit far though! Enjoy your new heater.

 

[JohnZ]

Most better digital stats have the capability to adjust cycle rates in their set-up menu. Look in the instructions for it. IMHO as a pro, a 2 degree drop is not short cycling rather normal. Most people can feel a 2 degree drop and start to get uncomfortable when the temps swing more. IMHO it is a waste of fuel as well. If you need a manual for your stat just let me know. And let me know if I can help you any further or if my understanding of your question is way off base!
Tim

Tim, it's just a typical el cheapo Model #1E56-301 SPDT 'stat; what would you recommend for a digital where I could adjust cycle rates?

 

[MyDomain]

Tim, it's just a typical el cheapo Model #1E56-301 SPDT 'stat; what would you recommend for a digital where I could adjust cycle rates?

This model from White Rodgers has the most adjustments to the "heat anticipator" which adjusts cycle rates. See page 9 of the manual, line 3. The lesser expensive models had only 2 rates, fast or slow. I hope this helps.

Programmable
http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-5748___1.pdf
http://search.ebay.com/1F97-371_W0QQfromZR40QQsatitleZ1F97Q2d371

Non-Programmable
http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-6071.pdf
http://search.ebay.com/search/search.dll?from=R40&satitle=1F96-344

 

[MyDomain]

Just checked your manual. It says nothing about an isolation relay so you should be okay with a digital.

 

[JohnZ]

This model from White Rodgers has the most adjustments to the "heat anticipator" which adjusts cycle rates. See page 9 of the manual, line 3. The lesser expensive models had only 2 rates, fast or slow. I hope this helps.

Programmable
http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-5748___1.pdf
http://search.ebay.com/1F97-371_W0QQfromZR40QQsatitleZ1F97Q2d371

Non-Programmable
http://www.white-rodgers.com/wrdhom/pdfs/instruction_sheets/0037-6071.pdf
http://search.ebay.com/search/search.dll?from=R40&satitle=1F96-344

Thanks, Tim - I'll study those two.