How to adjust honeywell round thermostat (mercury switch) to the right temperature

On Feb 23, 2:11=A0pm, harry wrote: It's important that the thermostat

That may be an exaggeration. I recently lived in Europe several years.

The heating I encountered was all hot water radiator (or hydronic - it is SO nice to step on a heated tile bathroom floor on a cold morning).

Every radiator had its own thermostat, mounted on the radiator. That's really not an ideal location. The furnace did have an outdoor sensor with reset and a time schedule.

Energy was expensive so houses were very well insulated and very tight.

On Feb 26, 2:58=A0pm, harry wrote: .The boiler(furnace in your parlance) can

I call it a boiler, too. But it doesn't actually boil anything, so to avoid confusion I used the word furnace. Sorry if I confused.

Also water is

Well, I'm talking mostly residential, though the office buildings I saw all had the same kind of hot water heat. There was no air conditioning except maybe in a computer server room.

Primitive? That's relative. In Germany I saw no VAV, no DDC, no control systems to speak of, thermostatic control valves on the radiator where the heat from the unit masks the room conditions, thermostatic valves that you have to disassemble monthly because they scale up and always fail to "no heat" condition. No smoke detectors, heat detectors, CO alarms.

On the other hand, I saw first class furnace/boiler systems in residential that were well maintained by law, including semiannual combustion tests and chimney cleaning. And as I mentioned, well insulated and well sealed; you can get infiltration down to near zero if you use plaster over masonry and very very expensive double pane tiltable-closable windows. I wish I could get those in the US but I couldn't afford it if I could. Even the doors are built with a lip to seal against the jamb. I was paying 27 cents a kWhr so you can see why they work hard to save energy.

I live in the UK. My house hase quadruple glazing and 4" insulated shutters, There's 2' of insulation in the walls and roof. This means we need no central heating. I have done all the work myself, I used to be an energy efficiency engineer working for the government.

It has nothing to do with the USA being "primitive". There are plenty of hydronic heating systems in the US, particularly in the Northeast (fueled by oil, natural gas, or propane), and they do give a nice heat (though they do take up wall space for radiators or baseboard convectors). However, you don't get air conditioning with that distribution system, so forced air is more common anywhere AC is desirable, now or in the future. Some houses (like the one I grew up in) do have both, but that's usually the result of retrofitting AC; a new home is likely to have only one HVAC system.

Josh

Well, you know how those darn colonies are. They rebel and go their own way.

TDD

quad glazing, 4" shutters, post a photo, is the quad glazing LowEArgon

No gas boiler can exceed 100% efficency, I know of none over 98%.

That's revolting.

It's revolutionary.

TDD

replying to Lp1331 1p1331, jeroboambramblejam wrote: Sounds like the sluggish mercury droplet had oxidized somehow - maybe a manufacturing defect allowed oxygen to enter the glass bulb... Or possibly excess electric current was allowed to course through the mercury droplet and change its physical properties. I think they are rated for ~24 volts AC from a transformer fed with ~120 VAC... If the transformer input side partially shorted, excess current could have been fed to the thermostat.

On Monday, February 22, 2010 at 5:07:14 PM UTC-6,

She froze to death since 2010.

"Glenda Copeland" wrote in message news: snipped-for-privacy@tioat.net...

It's probably easier to just replace the mercury thermostat with a digital. It'll be more accurate and have less temperature fluctuation. The little pointy thing is supposed to be aiming at whatever current amount the device it's controlling is drawing. It may be a relay or a zone valve, so you'd have to know this, then find the thing, then find the label on it where it give it's current draw. You could just point the thing far to one side, then see how it affects the temperature, then far to the other side, and make whatever adjustments you need. Keep in mind also, that Honeywell T-87 yo-yo thermostats must be level as well. There are marks on it, that you hold a plumb bob up to ,to properly level it.

Glenda Copeland wrote in news: snipped-for-privacy@tioat.net:

You can change it to digital therm. on your own. I did it so anyone can do it. Just don't allow the wires to fall back into the wall. Seeing that winter is half over, I'd wait until you don't need the heat. Then if you mess up, it won't matter so much.

Tell your husband that just because it's pointed to 85, it doesn't mean the air temp is 85. Get a room thermometer and set it near the thermostat. Then show him the thermometer's reading of the air temp. And tell him to mind his own business.... he he.

The adjustment you are talkig about s called a heat anticipator. RBM is correct in that is adjusted to the amperage draw of whatever the thermostat is controlling. The others are also correct in that digitals are much more accurate, and now a lot of them actually cost less than mercury bulb mechanical types. Larry

Agree with you and Ransley. First thing is to make sure it's level. Then if necessary you need a thin wrench that you can hold the nut with so the mechanism doesn't move while you rotate the dial.

All in all, considering the conveniences of a programmable digital one, I'd just replace it. Wouldn't it be nice to set the heat back at night and have it come back up shortly before you wake up?