Is there a way to add thermostats to hot water furnaces

Herb Segal

Thanks everyone for the responses.

My heating contractor came by the house and told us that the TRV solution is very expensive. He said that it requires additional piping off the radiators we want to thermostatically control.

Do you call agree? In my mind I thought all I needed was to remove the radiator and install a thermostat then reconnect.

Our heating man said to do TRV's only makes sense when you install a new heating system but they don't make sense on an existing system due to all the additional piping.

I live in Natick, MA. Is there anyone in my area that does this kind of work? I wouldn't undertake it if it does mean all this retrofitting of pipes.

Herb Segal

Is there a way to add thermostats to hot water furnaces

I have an old house with large hot water radiators. Two of the 2nd floor bedrooms with large radiators get very hot while my downstairs is cold.

Is there a way to regulate the heat with a thermostat on the radiator so the dowmstairs heats more and upstairs heats less? I assume the thermostat would turn off the hot water coming into the radiator.

I'd rather not re-pipe the entire house if possible.

Paul Pollets

TRV's

Have a contractor install a thermostatic radiator valve (TRV's)on each radiator. This will allow precise temperature control of individual radiators, with 1 thermostat. The pump should be protected with a PBD or pressure bypass differential, if using TRV's.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Mike T., Swampeast MO

To elaborate on TRVs

These devices have existed since before WW-II. They are reliable, surprisingly inexpensive, energy saving, and ultimately comfortable.

Grandpa can have his BR at 80 while you have yours at 65. "Setback" models that work with phone wire and a doorbell transformer are also available. You'll find "the bigger the radiator, the more comfortable you are." You'll also be able to raise the temperature in a space surprisingly fast.

TRVs are NEVER cheap, but they are not particularly expensive as valve geometry has not changed in all these many years and it's not too difficult to install them. You can use your old boiler with little change (none if there is already a bypass line).

Outdoor reset goes hand-in-hand with TRVs, but is not an absolute requirement. If you're in a topsy-turvy climate though, reset and outdoor cutoff really should be added at the same time. Simple mechanical (ratio and setpoint) resets are more than adequate for old cast iron systems unless you also produce your domestic hot water from your boiler.

Mark J Strawcutter

even more on TRVs

I agree, TRVs on all rads with constant circulation and outdoor reset is a good approach.

Another "first step" would be to install TRVs on your upstairs rads only. Allow existing (downstairs) thermostat to control system.

Finally, a very inexpensive alternative would be to do some crude balancing using existing valves - assuming you can get them to operate :-) Open them all up wide open. Let the system run for a few days/weeks to get a feel for what's hot and what's cold. Then start playing with the valves - throttle down the second floor for example. I've also heard of cases where partially closing downstairs rad valves can make them hotter (slows the flow).

Mark

Louie

Hot Water Controls

The prices for the controls are not bad, about 110 bucks.
Honeywell #T104F1512 Actuator (Grainger#3UC69) 65.00
Honeywell #V110E1112 High Capacity Thermostatic Radiator
Valve (Grainger#3UD06) for 3/4 45.00. Easy install!
They are the favorite around here. Ask your
heating tech what additional piping is involved with swapping out a hand valve or 90 with one of these?
Good luck.

Mark J Strawcutter

repiping and TRVs

The only situation I can think of where additional piping would be required to install TRVs would be with a series loop of baseboard or convectors. Given your description of your system, I doubt that you have a series loop but check to be sure.

Perhaps your heating guy has never installed TRVs or just doesn't like them for some unknown reason.

Try the "find a contractor" link at the top of the page to locate someone in your area.

Mark

Louie

TRV'S


There's a Wethead convention in Marlboro Maine
on 11-23-02. Maybe one of them would interested
in showing up a day early with their truck.
Side-Job anyone?

Mark J Strawcutter

additional piping

There could be another need for additional piping, but not around the radiators you equip with TRVs. If you put TRVs on _every_ radiator you'll need to add a differential pressure bypass valve to the system so the circulator doesn't deadhead when they all close down.

I still think I'd start by trying a couple of TRVs on those too-hot upstairs rooms.

Mark

Mark J Strawcutter

I'm a little slow

I'll bet he's thinking about having to bypass each TRV-equipped radiator to avoid deadheading the circulator.

Ask him about using a differential pressure bypass instead.

Mark