Cycling times & thermostat

BillW@honeywell

Go into "Installer setup" and set the stat to 1 cycle per hour. That's the recommended setting for a steam system.

Peter_11

Cycling times & thermostat

For a long time I had a standard round Honeywell thermostat. My gas-fired steam boiler would fire frequently but for short periods. It never seemed to build up too much steam as I would have to run around the house & remove the vents to allow the radiators to get warm then put them back on when it was up & running. Cleaning/replacing the vents didn't help.

I recently replaced the thermostat with programmable model. Now the boiler fires for longer periods of time and builds up enough steam to fill the radiators and the vents seem to work fine. I beleive this is right but it has raised other issues:

1) Even with its new success, it takes some time before the thermostat is satisfied so the the system builds up a good amount of steam. Often the vent valve at the boiler hisses away. Is this OK? Should I play with the settings on the thermostat more?

2) Now that (I think) it is working properly, I have picked up some more hammering sounds and need to track them down. My guess is the old pipes have never been cleaned out.

3) What is a good cycling time for a steam boiler system?

Thanks.

MIKE6

thermst

Sounds like the old tstat had a low amperage setting causing a short cycle any average tech should have spotted this.but I find about 25 of these a year that are out of adjustment tthat were installed by average techs.On steam the longer the cycle the better.The vent valve should allow air out if steam is comming out replace valve.I hope you mean the valve on the steam pipe near the ceiling.If a valve on the boiler is hissing like the relief valve shut down and have unit serviced.Hammering sounds try a boiler cleaner first,then look for water traped in steam pipes with no pitch towards the boiler

Damian_2

Thermostat and cycling-Anticipator setting for steam

This is for BillW@honeywell.

You helped out last week on my "really old 2 pipe steam system". Major short cycling issues.

Solve the problem by installing a Hoffamn 75 on my front loop return and also installed a new T-87 heat/cool t-stat.

It was significantly different than my old round honeweyll that must have been a demonstrator model for Mr. Honeywell when he patented the thermostat.

The new T-87 has an anticipator that I set at 1.2. with the new venting, I am getting nice long cycles. MY wife even stopped complaining about how cold it is and started complaining about the living room being too toasty.

Now I want to optimize this thing. Where and how do I start
in calibrating the cycling. Is my 1.2 ok or do you haveany other recommendations?