Can I replace my old thermostat?


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Old 07-29-08, 02:19 PM
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Can I replace my old thermostat?

I have a steam heat boiler with an old thermostat (this http://i241.photobucket.com/albums/f...e/IMG_2303.jpg ) which needs to be placed in a better location so that:

1). It doesn't shut the boiler when the 1st floor is warm while the second is still cold.

2). My tenants upstairs can also access it if they need to (if I can place it in a common area).

So, I'm thinking instead of paying over $500 to install another thermostat/break and repair walls to do the wiring, can I just buy a wireless thermostat and replace the existing one with its base and put it's remote wherever I want to.

I'm looking at something like this:

http://www.amazon.com/Lux-TX900RF-Pr.../dp/B000COHC3M

How about the wiring for this? Is it relatively easy to just replace the old one with this new one?
 
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Old 07-29-08, 04:07 PM
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You may be treating the symptoms and not the cause. You may want to get someone in who knows a thing or two about steam to take a look at the vents and piping.
 
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Old 07-29-08, 05:16 PM
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I kinda thought the same thing ...

When the upstairs tenants are cold, and crank the t'stat, what's gonna happen downstairs ?

I would first look at trying to get the home balanced by adjustment of the steam vents ...
 
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Old 07-29-08, 07:09 PM
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I agree here. Moving the thermostat may not solve anything. If you are heating two floors with one thermostat, the steam vents need adjustment. The furthest radiators from the boiler want to be open wider and the closest radiators should be set at a much smaller setting. Close radiators around 1 or 2, middle at 5, and furthest around 9 or 10. You must also make sure all the vents work properly. You should only hear air and not see steam coming from them. And once the steam gets to them, they should close.

Also, when you tell me you have steam heat I am thinking an older building. Maybe you need to be looking into better insulation.
 
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Old 07-30-08, 02:12 AM
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This is one of the reasons I strongly dislike steam heating systems in residences. There is NO easy answer to this problem.

The boiler will always be working off of the lone thermostat and no matter where the thermostat is placed it will be wrong for some of the rooms. The use of adjustable air vents will NOT help that much unless you use thermostatic air vents and even then you need something to start and stop the boiler.

Probably the simplest would be to install an electrical thermostat in each apartment and wire them in parallel so that either one could control the boiler. These could be fully programmable thermostats and they would need to be set to fire the boiler at the lowest acceptable temperature for each apartment. Once set they would not be touched by the occupants. To actually control the temperatures in the rooms with radiators the air vents would be replaced with non-electric thermostatic air vents and these would be adjusted by the user to the desired temperature.

The above scheme is not very efficient but it will give decent temperature control. The alternative is lousy control, a different type of heating system or a rather sophisticated control that is beyond the limits of this forum.
 
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Old 07-30-08, 03:35 AM
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Make sure the mains are insulated properly. Make sure the main vents are operating and correctly sized, per advice above.

A key for steam systems is to have a thermostat that has adjustable cycles per hour (cph). Thermostats typically come preset for something like 6 cph, which is fine for forced air but not steam. For starters, you want to run a steam system at 1 cycle per hour. If your system is well-insulated and well-vented, etc. then maybe 2-3 cph so you can take advantage of the system's thermal inertia.

For thermostats with steam, the Honeywell VisionPro series apparently do a very good job. TH8110, TH6110, and TH5110, would all be fine, depending on what features you want or not. They are not wireless. Possible/probable you could get similar features in a Honeywell wireless.
 
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Old 07-30-08, 05:56 AM
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Tenants

You mentioned that the second floor residents are tenants. It's funny but for some reason tenants never mind having too much heat, they just open some windows. But in this case it would save you in fuel savings to have someone who really is a steam expert to balance the system. Pay now or pay later and then some.
 
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Old 07-31-08, 01:56 PM
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Have a steam pro balance the system properly, and if it's a 1 pipe system you can get these for the radiators individually:

http://www.homeenergy.org/archive/he...96/960509.html

Might be a good thing all around.

HE


Originally Posted by stuck_old_house
I have a steam heat boiler with an old thermostat (this http://i241.photobucket.com/albums/f...e/IMG_2303.jpg ) which needs to be placed in a better location so that:

1). It doesn't shut the boiler when the 1st floor is warm while the second is still cold.

2). My tenants upstairs can also access it if they need to (if I can place it in a common area).

So, I'm thinking instead of paying over $500 to install another thermostat/break and repair walls to do the wiring, can I just buy a wireless thermostat and replace the existing one with its base and put it's remote wherever I want to.

I'm looking at something like this:

http://www.amazon.com/Lux-TX900RF-Pr.../dp/B000COHC3M

How about the wiring for this? Is it relatively easy to just replace the old one with this new one?
 
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Old 08-01-08, 05:30 AM
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Thank you everyone for your responses. I learnt a little more about the steam systems last year, thanks to this forum. And it's a two pipe system.

However, the reason I wanted to change thermostat with wireless was because I'm going to have to move it anyway.

I was hoping to be able to move it to a common area and not in the tenants apartment. This area has one radiator that I know when it gets hot, the heat has reached most but all the radiators in apartment upstairs. So if the thermostat functions based on this Rad in common area, it will be relatively better. I have found this Radiator to be a good indicator of the heat upstairs, probably because it is at the far end of the loop maybe?

The place where it is right now, the boiler used to shut off every 10 minutes, and 10 minutes by no means is sufficient time for steam to reach upstairs and it is a ridiculous loss of gas. I used to pay over 500-600 each month in heat bills last year. I have tried using different sized air valves on the radiators but that didn't help much.

Plus, in case if we go out for a weekend, tenants have nothing to control the heat.

By the way, sometimes I do think that it's better I replace the entire system with something else, rather than pay around 500-600 per month for 5 months every year, but haven't been able to find a low cost alternative to central heating with ducts

So for now, I'm just hoping to be either able to move the thermostat or just replace it with the wireless one, if it is possible??
 
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Old 08-01-08, 06:55 AM
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First try a wireless thermostat. Your plan for location sounds good.

As above, the key feature you need is an adjustable cycles per hour setting.

This one has 1, 3, 6 or 9 cph. 1 or 3 should be good for your steam system.

http://customer.honeywell.com/TechLi...0s/69-1535.pdf


Before going down the path of replacing the heating system, you need to get a good steam pro (or DIY) to look at the insulation on the mains, and how the mains themselves are vented. Not just the vents at the radiators.

Also, you could very likely switch the steam over to forced hot water. There are a number of potential issues, but that would be a way, way better option than (yuck!) forced hot air.
 
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Old 08-01-08, 04:38 PM
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I'm pretty sure that if you go with a wireless, there's no reason at all that you couldn't have TWO thermostats controlling... If they're wired in parallel, whichever one was set higher would be in control.

The 8665 Honeywell does not have a dry contact closure output though... to my knowledge of it, it switches the 24VAC HOT output. I think if you wired it in parallel you would need another relay in between the receiver and the other t'stat (which I think you said is standard 2 wire ? I'm too lazy to read back, sorry!)

I haven't looked at any other wireless t'stats, but there could well be one that has a dry contact closure that you could simply wire in parallel with the existing... and perhaps replace the existing as well, with one that you can do the CPH thing as X suggests...
 
 

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