Steam heat and Programmable Thermostats, good idea?

Mark K

Hi all,

I am trying to keep my heating bills from killing me this winter. All the DIY sites say to install a programmable setback thermostat and set the temp back at night and during the day.

I've read a few posts on this site, and others, which suggest that this might not be a great idea with a steam system, due to the pipes getting stone cold when the temperature is set back.

I did have asbestos insulation on my steam pipes removed, and I've replaced it with the molded fiberglass wrap. Since the mains are insulated, does that mean that the temperature setback will save money as intended?

Thanks for the input!

Jay_12

tekmar Steam Boiler Reset

Hello Mark,

The tekmar 269 Steam Boiler control adjusts the on time of a steam boiler based upon how cold it is outside. You can optionally install indoor sensors as well.

Basically the control varies the on time of the steam boiler depending on how cold it is. If it's really cold outside, then the on times for the steam boiler are long, likewise if it is relatively warm outside, the on time is shortened.

If you have any questions, please contact me.

Jay www.tekmarcontrols.com 1-250-545-7749

Firedragon_4

People will drive you up

'the wall' and you will get tons of advice, but a thermostat can do the job and very well.

Keep in mind that a Btu, is a Btu, is a Btu and all fuel burners are only 100% efficeient when shut off, FACT!

Go here, do some reading and spend a few bucks on a good simple thermostat the will do the job: http://content.honeywell.com/yourhome/ptc-thermostats/thermostat.htm

hvacfreak

Do you think this will be the year we start converting oil back to coal. I wish I could. Petrol prices are out of sight already.

Sean_5

Recommended Thermostat for Steam One-Pipe system?

I appreciate this question as I've had a similar one. I recently replaced all the air vents on my one-pipe steam radiator system and insulated all the pipes with fiberglass wraps in hopes of improving my system's performance. I set the adjustable vents as recommended with the closest radiator to the thermostat with the slowest air vent setting.

When I moved in years ago I thought a digital programmable thermostat was a good idea and installed one. Now I wonder if it's part of the problem. The boiler seems to cycle on and off quite quickly. Before steam really gets to some of the further radiators, the digital thermostat shuts the boiler off. Is it inefficient for the boiler to be going on and off so frequently? The thermostat does this to keep the house at temp, but turns on when it drops just one degree, and off when it comes up one degree. I wonder if this is really how the system was designed to work.

I went to Honeywell's main thermostat website and searched around - they don't really seem to have a recommended thermostat for a steam system. Is a simple 2 step manual thermostat a better idea than the programmable type - or does it not make a difference? (and maybe it's something else). Thanks!

T. Hunt

Are you sure your system wasn't short cycling with your old thermostat? Short cycling is usually a symptom of a boiler oversized to the radiation load attached to it.

T. Hunt

I wish I could see your post when I'm replying
You mentioned buying new vent valves, are they adjustable? If the boiler is shutting off before the distant radiators have filled with steam you can open the valves on the hard to heat radiators fully and lower the setting on the radiator(s) closest to the thermostat.

Boilerpro_3

Check the anticipator setting

Or on Honeywell stats the cycles per hour setting. They are factory set for forced air and steam needs a much different setting, typically 1 to 3 cycles per hour. Did you have large main vents on the system steam mains? If you do the geography method of venting is largely inapplicable.

Boilerpro

jackchips_2

T, you can

see the post you are replying to if you hit the reply key to that post. You just scroll up when you in the post reply box. I can see yours now.

BillW@honeywell

The steam/setback controversy...

is complicated. Steam systems have a "flywheel" effect,
which means they stay warm long after the boiler shuts down. How long depends on the building envelop,ie insulation, tyvek wrap, windows etc. Any of our new electonic stats should be set to 1 cycle per hour for steam systems. Out of the box, they are set for 6 cycles per hour, the usual setting for forced air. If your vents are working, mains are insulated, and your boiler is running right, you probably can use our FocusPro 5000 thermostat. It is NOT programmable, and it is very easy to use, has a large screen, +- 1 degree electronic accuracy, and is mercury free. Part number is TH5110D1032, and it's available from any Honeywell distributor. There is no retail equivalent.

When you get it, use your owner's manual to set it for 1 CPH, and of course, follow the mounting, wiring & installation recommendations.

Sean_5

Steam thermostat issues....con't.

My radiator vents are set properly, but I don't have main vents installed - something I'm looking to do soon.

The house is old, and has a lot of air penetration, so it gets cold fairly quickly.

I'm a bit ignorant about the oversized/undersized boiler issue so maybe I need to learn more about that and/or consult a pro.

Is the above mentioned CPH (cycle-per-hour) matter possibly the issue here? I installed the programmable thermostat out of the box. I have no idea about what the CPH means or how it works. Would a lower CPH mean the boiler turns on and off less frequently but runs a lot longer? Will this cause greater swings in home temperature (like the mecury's seem to do)? Can I possibly reprogram my current stat? Thanks much!

Jeff_17

Bill...does that model

work with a millivolt gas system.? I HATE the 7-day jobs...but would love a simple digital to work my system!!

BillW@honeywell

Yes!

The FocusPro and it's programmable brother the VisionPro can be used with the 750 MV "millivolt" systems. The stats are battery powered or can be hard wired.

Boilerpro_3

Very likely the issue

I find it all the time on both steam and hot water. Few contractors in my area know the proper settings. Those short cycles will aloso really hurt efficiency and tend to cause sooting of the boiler.

Boilerpro

BillW@honeywell

Seal up and save...

A thermostat can help save energy, but there are some basic, inexpensive steps you can take, many of which you can do yourself. Seal up the electric outlets & switch plates on outside walls. Weatherstrip the windows and doors, or if it's in your budget, replace them with EnergyStar rated windows and doors. You can add insulation yourself, but a pro can get you the dense-pack cellulose, tyvek wrap and/or the icenyne foam that work best...fiberglass only slows the heat loss down. Use insulated draperies, and leave the south-facing window treatments open in the winter, to catch some "free" sunlight.
Any thermostat will call for heat when the temperature drops below the set point. The number of times this happens depends on how fast your home loses heat. The number of cycles per hour is the electronic equivalent of the old heat anticipators in the electromechanical stats to prevent over/undershoot in the system.

Mark K

Still Confused

Hi all,

Thanks very much for all the advice and resources. I'm still not quite sure that my original question was answered, though.

BillW, thanks for all your advice, I appreciate it. I actually have had Mass Electric come to my house and tighten up with air sealing, and additional insulation in the attic, basement and walls. New windows are out of the budget, at least for this winter. I have triple-track storms on all of them, though. It's an old house (ca. 1900), so it's not as tight as a newer one, even with all the improvements.

The current thermostat I have is reasonably new, a Honeywell mechanical one, which probably dates to when the boiler was installed, in 1992.

So, here's my question again...I don't like to keep the house very warm during the winter. My old house, I had the setback thermostat set at 55 days/nights, and 65 evenings/weekends. I have some nice sweaters that I like to wear at home If I do that with a steam system, do I get the same savings as I would with a furnace or hot water system?

Unknown

Yes

The savings will be there.

The system starting cold every day will act differently than if it ran at one temperature all of the time.

If you can get accustomed to those differences, you'll have no problems. Each system will have it's own perks.

Let us know how it acts that is a change from just letting it run at one temperature.

There isn't a problem WITH setback thermostats, they're fine.

The problems would be the same if you used your old thermostat and did the setback manually. The problem is the cold startup and the overshoot of room temperature, not the control itself.

Cold start-ups can be interesting. I hate the 6 AM phone call that starts with, "This never did THIS before you put that thermostat on!!!"

Noel

Zorian Pinsky

Programable Thermostat does work

Hi!

I have steam heat in my house and I have been using Honeywell programmable thermostat for 3-4 years. I bought it in Homedepot for about $100. The main feature of the thermostat that is beneficial in our situation is that the thermostat memorizes how much time it took to heat the air to the set temperature. Next cycle, it starts the boiler so many hours before we come home or wake up...

Good luck!

David Efflandt

Auto anticipator and ramp up

Two things a good electronic thermostat can do is automatically learn anticipation to minimize overshoot: by comparing and remembering rate of change of wall and air temperature, and ramp up from setback (instead of all at once). Although, they may overshoot a bit if you get a sudden mild day after cold weather. My Honeywell electronic thermostat works quite well even though it is a consumer version instead of the better commercial version.

My thought (1-pipe) is to use more setback in mild weather to eliminate boiler cycles, since if the boiler is not going to run for several hours, might as well not run it at all (except morning before I get up, and evening if not enough solar gain from windows). In cold enough weather that the boiler/piping stays warm, I set a steady temperature (~67F) and bump it up a degree or so in the morning so rads are warm when I get up.

cloudsrepair

Not all T-stats are ok.

I am having difficulty finding a standard single pipe digital programmable, such as found in old Hotels. A standard two-pipe would be fine too.

An off-the shelf digital programmable is unacceptable on some levels.

a. Most likely have to re-program to allow the system to cycle. Not terminal, just irritating, clearly a sign of a wrong application. The first sign of fighting physics.



b. In my application, the thermostats coded a low power alert.

I am switching an overhead radiant, which will blow cold air if it doesn't cycle.

Also it uses maybe 500 watts for the induction fan.

Ordinary line thermostats expect a baseboard or electric radiant, so they can not be relied on, for example on a remote farmyard, the low power alert is a terminal flaw, I had to put the straight line one back in.

I am also adrift as to whether the yard had power issues, but suspect the above conditions may have been the cause.

I have used commercial pipe-controls in Hotels, but seem unable to find a wholesaler who can find one.

Any help would be appreciated.

Thank You !

nicholas bonham-carter

Buried in a 10 year old thread.

Why not start a new thread for your question in the steam section, stating the type of system you have, what you wish to do, and any symptoms you encounter.

We really don't know if you have resistance heat, or steam, and is it a barn or an old hotel?--NBC