Radiator Supply Valve (Updates)

garfungle

Hi,

I'm getting ready to refill my hydronic (hot water) boiler and I want to be sure that I can control all of my radiators. I noticed that all of my supply valves to the radiators are stuck. They are all an old 1920s style valve. I've decided, while the system is drained, I would add TRVs to every radiator. Reading through the forum, it seems it's much easier to repack the valve than replace it. I had a couple of questions regarding this:

1. I'm not entirely sure, if I can just upgrade in place the valve handwheel with a TRV head or if I need to entirely swap the valve.
2. I was practicing on a radiator that I had removed and took the handwheel off and removed the packing nut, but the stem still does not move. I know I could hit it with some PB blaster, but I'd like to be sure that the valve stem is still even intact. What are the best ways to check the stem?
3. Should I just replace the entire valve?

I've attached pictures of my disassembled valve on the riser. I noticed some white material below the packing tape that seems like really old teflon tape. I'm guessing this is some sort of packing material.

mattmia2

If the packing is white and fluffy it is probably asbestos. I can't tell if it is fluffy or slippery from the picture.

There is another part of the valve that unscrews that contains the threads and the packing gland, that is where you want to take it apart to rebuild it.

You need to replace the valve to add a TRV actuator. There are manufacturer specific valves designed for different brands of TRV actuators(and some brands have more than one style and some brands are interchangeable or adaptable). The short answer is you need to change the valve or add it inline somewhere.

garfungle

I didn't realize that was asbestos. It's definitely fluffy and I moved some of it around and now have a sore throat. I wasn't wearing proper PPE, so hopefully I wasn't breathing in too much. If all of the other valves are stuck, rather than dealing with the asbestos, do you think I should just upgrade all of the valves while the system is drained. I don't really want to mess with these stems if they were using asbestos as the packing material.

There was only one location that I was able to get channel locks onto this valve, so I'm not sure where else I would torque. I can attach a link to another post that is pretty identical to the valve that I have who had a similar problem.

https://forum.heatinghelp.com/discussion/189943/1920s-radiator-valve-stuck

This valve is pretty much identical to mine.

mattmia2

Oh. If that is the type of valve you have they are plug type valves and you likely will have to remove the valve to clean it up and get it un-stuck. You probably would have to soak it in citric acid or something like that or figure out how the stem is held in and remove the pin or whatever holds it in.

garfungle

Ok, so something like pb blaster might work to help loosen it? Does it change anything from before as far as working with TRVs or basically any work repairing these valves risks asbestos exposure and can't actually repack to a TRV head.

mattmia2

A TRV uses a different style of valve with a pin that the actuator pushes on to open the valve.

If you keep that asbestos wet and contain it I wouldn't be super concerned about that small an amount. You could just add some teflon or graphite string packing if you are trying to stop a leak instead of digging the old packing out.

Since the valve is probably covered in iron and other mineral deposits on the water side that are holding it in place, penetrating oil isn't likely to do much unless you remove the valve and put it on the water side. Gently rocking it back and forth with a wrench that fits the stem well might get it loose.

Be careful about what the overall system effect of TRVs is if you add them. If they cause only a radiator or 2 to call when there is a heat call it is likely to cause the boiler to short cycle. If it is a monoflo system you generally can't use TRVs, they will throw the system out of balance.

garfungle

My thinking is to keep the TRVs isolated from the heating controls. TBH, I don't really need TRVs, I just wanted controllable valves. I'm planning on using home assistant to control the TRVs and balance the thermostat calls to prevent short cycling. I will call for heat from rads that will always be open and in the same room that the thermostat is located. The TRVs are really just for zone heating without repiping the whole system or adding a zone board and will mostly be used in an on off configuration depending on the overall balance. This could be also a very stupid idea since I acknowledge that a better way would be to pipe it with a zone board.

garfungle

I'm not trying to stop a leak here. I'm figuring I'll need valve control to rebalance the system since every valve is currently stuck and I've drained the system and removed a radiator from the loop.

garfungle

Also, my valve is not on the return side like that post shows. It is on the supply side, so I'm not sure if that changes anything you were saying before about penetrating oil not having any sort of effect.

JUGHNE

Have you looked at any TRV's? All that I have seen are meant to replace the existing supply valve. They would be of the 90 degree configuration. You want the temp sensing element sticking out to the side, rather than on the top of the valve where is is effected by the riser pipe heat.

If you change the supply valve or put a TRV in for a controllable supply valve, you have to change the spud that screws into the radiator. It is brass screwed into cast iron.

There is a spud wrench that will insert into the spud once you have the valve out of the way.

It usually just breaks off the tabs inside of the old spud. Then you have to get creative on how to remove it.

You could cut the union nut off out of the way, insert something solid into the spud to prevent it from collapsing and try a pipe wrench on it.

If that fails as it often does, then saw the spud off leaving about 3/8" sticking out of the rad. Then with a hacksaw blade you cut segments out of the spud without hitting the CI threads of the rad. Then with the proper chisel you can knock one segment out and get the spud to unscrew.

I believe you said you did remove a radiator. That would be a good practice victim for removing spuds.

EdTheHeaterMan

@garfungle Said: My thinking is to keep the TRVs isolated from the heating controls. TBH, I don't really need TRVs, I just wanted controllable valves.

the TRV valve body is usually more expensive than a replacement manual valve, and that does not include the actuator head. If you don't need them then use manual valves. One reason for a TRV is to place that type of valve on a radiator in a room that overheats, compared to the rest of the rooms in the home/building. It gives the person occupying that overheating room the adjustment needed to keep the room from overheating. Otherwise the only other way to control the room temperature is to open a window to let in as muck cold air as possible to overcome the overheating radiator. Landlords don't like to see open windows in the middle of the winter.

Another reason is to have no room thermostats and operate the boiler at a constant temperature or on an outdoor reset temperature. As each radiator senses that room to be cold, the valve will open to the flow of the constant circulator operating with hot boiler water. Much less wiring of controls from each room or apartment to the boiler control room.

@garfungle Said: I'm not trying to stop a leak here. I'm figuring I'll need valve control to rebalance the system since every valve is currently stuck and I've drained the system and removed a radiator from the loop.

I hope your radiators are not in a series loop. They should be individually run to a Tee fitting on the main supply, with the other side of the radiator running individually to a Tee fitting on the return main.

So… was the system balanced before you took that radiator out?

1. YES = leave the valves alone
2. NO = replace all the valves with manual valves while your system is drained.

You will need a spud wrench to remove the union fitting (called a Spud 🥔) from the radiator. The replacement valves will not match the existing Spud 🥔

garfungle

@jughne I've looked at both the danfoss valve bodies and then swapping the head for a sonoff "smart" TRV to make them remotely controllable. The danfoss bodies themselves are expensive, that's why I was thinking it might be possible to retrofit the 1920s style valves since I don't really care about the temperature sensor in the TRV, just the fact that I can remotely actuate it, hence why I'm looking at the smart TRV. The main reason I've been doing this on the valve with no radiator is specifically for practicing before I try to do anything else haha, so you're right, it makes a good candidate for practice.

@EdTheHeaterMan My reasoning for using the TRVs is exactly as you stated. When I said I don't really need TRVs, I meant I don't need the built in temperature sensing, I just want something I can remotely turn on and off based on a schedule (e g prevent bedroom from overheating at night). Smart TRVs were the only thing I've seen marketed this way with radiators, but I'm using them simply as remotely controllable radiator supply valves. My main concern with leaving the valves as is is that they're all stuck open. I have no idea if they are balanced, but I'm worried that if they aren't balanced, I'm going to have a headache on my hands because I can't balance the system after I refill, so I'll need to drain again. But I also get the risk of damaging the old pipes if I can't correctly swap the valves.

hot_rod

that stem may be damaged beyond repair?

You need a new valve, or the TRV upgrade