Thermostat Help Needed

There must be at least one HVAC expert here.

Uh huh, but it isn't me. I'm surprised there's not a control for duration of cycle. I would just replace the unit. Take the old one along when you go shopping.

I moved the sweep to .6. Now the heat stays on longer. It's also warmer in the house, and I've had to reduce the temperature setting.

In a two story home, shouldn't there be two thermostats, one upstairs, wired in parallel? I only have one.

You'd never wire thermostats in parallel. In newer houses you'd have multiple "zones" - each with their own circulation pump - and each zone (typically each floor would be a seperate zone) would have it's own thermostat.

The thermostat you have is an antique! You might be well off to replace it.

I asked the landlord to replace it, they didn't, or they replaced it with an identical one. This place was built in 1998. Where did they find it?

It's a multi-story house built within the last 10 years and it only has one heating zone? Someone built that place on the cheap!

Whoever built the house must have found that thermostat on a shelf somewhere. Honeywell doesn't even list that model in their on-line support files any more.

It's a T822D. The number I listed before was apparently just for the housing.

Ah! You should have said that earlier!

http://customer.honeywell.com/Techlit/Pdf/69-0000s/69-0510.pdf

Well, I'll look for an amp rating, I didn't see one. Where exactly do I look, based on what that says?

The thermostat controls a relay that should be mounted next to your furnace. The relay box should list the amperage.

To find the relay box find the power cable that connects to your circulating pump and follow it back. (The relay is usually mnounted with a few feet of the pump.)

So, what if matching the amperage to the sweep setting causes the thing to constantly cycle on and off? That is what it was doing before, set at .4. I changed it to .6 just for the hell of it and now the cycling isn't so bad. Still not great, but not as annoying as before.

The high/low limits on the relay box may be out of whack. Did you live in this house last winter too? If so, did it do the same thing?

There should be a "High" and "Low" setting on the relay box. Thiose settings determine how hot the furnace gets the water in the system. If you set those up higher the radiant systems will have more heat to give off before cooling. You might check the settings and see if they can be upped a bit.

It's possible that what you are getting was done on purpose. I know that when I replaced the furnace in my place back in the mid-1990s I was told that it is better to have a slightly undersized heating system that runs more often then an oversized system. Supposedly the furnace is more energy efficient if it cycles more often in shorter bursts. I don't know if the heating pros still go by that or not.

No, I didn't live here last year. I don't know what to think anymore. All I know is what I did achieved (sort of) the desired result. I don't know if there are any adverse consequences to doing it though.

FYI It is a forced air gas furnace, there is no water involved in the heating process.