Adding TRVs?

DJDrew

We are redoing a bathroom on the first level of our house and installing new radiators, because of the way the system is piped, we had to drain the whole system.

While the system is drained, I am considering replacing the 3/4" radiator valves on the second level of the home with 3/4" Danfoss TRV valves. For years we have had to partially close the upstairs radiators to balance the system and keep the temperature somewhat in-check upstairs (always 3-4 degrees warmer it seems).

Is this wise choice to use this system downtime while it is drained to make the swap to TRVs for the upstairs bedrooms? Or am I better to just keep throttling the flow with the existing valves to keep the temperatures in check?

Thoughts?

Zman

TRVs are a great product that, IMO is underutilized in the United States.
Do you know how your system is piped? It may not be as easy as it sounds.

DJDrew

Thanks @Zman - Yes, each hot water radiator is piped direct to the basement and into large supply/return pipes circling the entire house. The 1930's must have been a time for iron-pipe water highways in houses.

mattmia2

It was originally a gravity system.

wesPA

I would definitely recommend it, especially if you have things drained to do the remodel work. I installed the danfoss valves on the system at my house about 5 years ago, and have been very happy with the results. Like you, all my rads are piped to the basement,  and I had temp differences floor to floor prior to the valves 

Jamie Hall

mattmia2 said:

It was originally a gravity system.

Most likely. And I'll bet when it was converted to forced circulation no one thought to place balancing valves on the radiator runouts. TRVs will help -- assuming that it really is piped home run or parallel, with no series elements -- but while you're at it you might consider balancing valves as well and get it as close to even as you can that way, and then let the TRVs do the fine tuning.

DJDrew

Jamie Hall said:

mattmia2 said:

It was originally a gravity system.

Most likely. And I'll bet when it was converted to forced circulation no one thought to place balancing valves on the radiator runouts. TRVs will help -- assuming that it really is piped home run or parallel, with no series elements -- but while you're at it you might consider balancing valves as well and get it as close to even as you can that way, and then let the TRVs do the fine tuning.

@Jamie Hall Would that be essentially moving the manual valve to the return? Or leaving the manual valve alone and just fitting the TRV on the return?

mjstraw

TRVs should go on the supply or else they'll make noise.

EricPeterson

My house is also a converted gravity system.
After we moved here and experienced overheated second floor bedrooms, I installed TRVs on all the bedroom radiators. It works great, and you can also shut off the rads when not needed (we are empty nesters).
I did not however install TRVs on the bathroom radiators, because no one ever seems to complain (at least in our family) about bathrooms being too warm.

jumper

mjstraw said:

TRVs should go on the supply or else they'll make noise.

Why?