Thermostat out of level

Fizz

Fixing-up 2nd house, hoping to down-size, when I noticed boiler short cycling at 65 degree setting, yet on 70 setting it over heated, manually shut-off cycle. On looking at t-stat(honeywell vertical mercury), I removed cover to clean and noticed base plate is out of level. Thinking this is reason for above. If so, how does one properly balance(dumb question)? System is oil(WM), single pipe.

EBEBRATT-Ed

Level thermostat...baseplate with a.............level!! Mercury thermostats have to be level to be accurate but will work when out of level....to a certain extent

JUGHNE

If vertical rectangular t-stat, then should be plumbed with level.
It would probably have an adjustable heat anticipator inside.

Fred

On a round T-stat, there is usually two tabs near the top of the base plate that you can set a small level on to level it up.

Fizz

It's a vertical, rectangular t-stat. That's what I thought. Thanks.

BobC

I had a vertical Honeywell in my apartment in the 70's but it was a bimetal spring that had contacts, it turns out those contacts were silver and a dollar bill was all you needed to clean them.

In my case I noticed a lot of temperature swings and found the thermostat was mounted on a wall which had a steam pipe to the landlords apartment on the second floor. I put a T87 on the wall around the corner that had the bonus of "feeeling" the NE wind that plagues 1920 houses in my area.

Bob

unclejohn

Check the heat anticipater.

Fizz

Ok, thanks.

Big Ed_4

You would need the HoneyWell flat wrench to calibrate further once the thermostat is level ... The nut is behind the anticipator .

Fizz

Now that's interesting!

Big Ed_4

lock the adjustment lever at the room temperature ... Keep your warm hands away from coil behind anticipator .. Turn with wrench until the mercury falls over .. Its around 4* diff .. I try to get even or center ..By turning wrench back and forth

Disconnect W and R , Check the amp draw .. .2A -.4A will be the norm current of the control ...Set anticipator to the current as a start point .. Seems to over heat set to an shorter cycle

Fizz

Ok, the thermostat is a t822D, vertical. I now have it level. Anticipator was set at .2, the dial goes from .08-to .8, with "Longer" scribed on lower part and arrow pointing to direction of higher amps. So, for longer cycle move it to right, for higher A and longer cycle?

Jamie Hall

Yes, sort of. The whole idea of the anticipator is to do just that, though -- it lets the thermostat anticipate how much heat is left after the thermostat shuts off, which will continue to raise the temperature in the space to what you think you set the thermostat at. The setting controls the amount of anticipation -- setting it towards the higher current end actually lowers the amount of anticipation (sounds backwards, but it really isn't).

It isn't intended to control cycle length as such, but overshoot. If one doesn't mind the overshoot, then yes you can go to a longer cycle by going to the higher amperage.

Fizz

Jamie, that helps. What would be a good setting on the scale listed?
Fizz

Jamie Hall

Fizz said:

Jamie, that helps. What would be a good setting on the scale listed?
Fizz

Frankly, I wouldn't venture to guess. Different boiler controls take widely differing current. If you have any way to measure the current draw through the thermostat (some multimeters can do that) that current would be a decent place to start fiddling from.

acl10

Where do you get the Honeywell flat wrench?

Fizz

Thanks Jamie.
Don't have wrench, just moved anticipator with pencil.