Boiler radiator valves siezed

Ghynes440

We recently moved into a older 1890’s house which has a oil boiler radiator sealed system. We are converting to gas combi boiler this summer when we run out of oil.

Currently 80% of the radiator shut off valves are seized and do not close/open. I’m pretty sure the system is very imbalanced as we have a two rooms in the back of the house where the radiators do not get any heat.

My question is when summer comes, is it doable for me to close off the supplies at the boiler for the radiators and change all the valves on the radiators? I am very handy as I do a lot of work myself on everything, but radiator heat is new to me. My thinking is since it’s summer we don’t need the radiators so I can just shut them off at the basement and drain each radiator and replace the valves. Maybe even take them out and flush them?

When it comes time to replace the boiler the pro can come in replace it, fill it up and purge, balance and set it up the right way?

Long Beach Ed

Changing old American made radiator valves for modern Chinese ones is probably more work than it's worth for several reasons.

New radiator valves come with new union spuds, which are generally installed in the radiator. Since the valve and the spud are matched, the spuds must also be removed from each radiator, which is an exhaustive job.

The height of radiator valves - that is the distance from the top of the pipe riser to the centerline of the radiator outlet - as well as the spud length is not standardized. This means some risers may be too long or too short, and may not be easily adjusted in height where they protrude from the floors.

You should be able to free up the original valves. We'll assume yours are common, compression-style radiator valves. You can send a picture and we'll confirm that they are serviceable. Most any common American-made valve is serviceable.

Spray the stems with a penetrating oil, like Kroil or Liquid Wrench. Do this daily for a few days. Try easing the knob back and forth and tapping on the shaft. The shaft enters the valve through a "packing nut". Under the nut is replaceable graphite impregnated packing string, which has probably seized onto the shaft. Loosen the nut with an open end wrench and spray the threaded stem under it with penetrating oil if necessary. By working this way, you will free the valves and make them workable again.

If the handle is missing, you can grab the top of the shaft with a small adjustable wrench, or in the worst case, with a Vise-grip.

If you can't use these tools, you can hire a qualified mechanic or fitter to do this work.

Replacing quality valves with contemporary imported junk should be your last option.

Jamie Hall

You neglect to mention — is this hot water? I assume so, since you mention a gas combi boiler (which is a can of worms in itself; it's rare for a combi to be correctly sized for both the heating and the domestic hot water).

If so, as @Long Beach Ed said, those are likely to be quite normal valves. They are — unless someone has messed them up — easily repairable with a little patience.

The two radiators which don't heat may be air bound — unless the valves are closed (always a possibility) — which is fixable easily enough.

delcrossv

Loosen the packing nut 1/2 turn, then use penetraiting oil.

Pictures please.

Ghynes440

here are some Pictures, it’s not a bad combination boiler yet, currently an oil boiler that heats our hot water as well.

https://forum.heatinghelp.com/discussion/comment/1845886#Comment_1845886

Jamie Hall

Those are good old fashioned plain vanilla radiator valves. They can be disassembled quite easily and brought back into splendid operating condition. As has been suggested, though, a little penetrating oil on the packing nut will make life a lot easier…

No need to replace them. With a little care and maintenance they will still be working just fine long after a shiny new valve has gone to the dump.

PC7060

https://forum.heatinghelp.com/discussion/comment/1845914#Comment_1845914

if updating, I recommend Honeywell Braukmann TRV. I converted 19 radiators in our old house pretty straight forward.

Ask this old house video covers it well

https://youtu.be/_44vzZvmFLM?si=f3iWgmaVI02SKUwA

sometimes the spuds can be difficult to remove. When that happens I typically cut the nut off and use pipe wrench to remove.

pecmsg

why a combo boiler. Your not going to get a return on investment.

delcrossv

This one needs to be repacked for sure.

Jamie Hall

Why does it need to be replaced? Looks like it might have been weeping a little — but I don't see physical damage to the valve body.

mattmia2

you will need to use some scotchbrite or something and clean up the stem where it goes through the packing. they were left leaking for a while and the stem corroded, that is why they are stuck. take off the knob and packing nut and clean the stem then use some string packing to augment or replace the packing. if you dig it out and replace it with teflon string packing it will be more durable. the old packing frequently was asbestos or asbestos and graphite so keep it wet and contain it when you dig it out. sometimes it is just cotton or other felt.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1845953#Comment_1845953

Repacked, not replaced. 😉

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1845964#Comment_1845964

Tired old eyes… sorry.

Ghynes440

https://forum.heatinghelp.com/discussion/comment/1845932#Comment_1845932

Is there any video's you recommend watching to do this? Do you think it TRV valves would help with temperature balancing in rooms? or just a good balancing of these old valves will be just as good?

mattmia2

I would star with getting the valves working then closing some partially to balance. TRVs will take some work to make fit there, if too many are off it will cause the boiler to short cycle, and they won't solve an out of balance system issue. TRVs are better used to solve a problem with a room that is too hot and too cold at different times because of varying loads because of things like cooking or the sun or maybe it is where the outside door is. you should get the system in balance first then install a couple if you need to solve a problem.

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1846204#Comment_1846204

I don't really know of a good video for that… it's pretty simple. How much taking apart you need to do depends on how worn they are,

Make sure the system is off…

First step is… does the handle turn at all? Either way? Don't worry about leaks at this point. If it doesn't, penetrating oil where the shaft goes into that top nut, but don't be generous. A little will do fine. Keep trying to turn the shaft. If it gives, even a little, next step. Which is to remove the handle — there will be a screw on the top and it should just come off (maybe with some gentle persuasion) when that is removed. Now find a wrench the right size to fit the flats on the packing nut — the smaller upper hex nut. Do NOT use a vise grips or pliers, but a quality crescent wrench will do if need be. Unscrew that nut. Inside is the packing — or what's left of it — between the shaft and the body of the valve. With a handy pick remove as much of it as you can (all of it if possible). Go to the hardware or big box store and get some packing material — it's like a thick string — and wind that into the space between the shaft and the valve body, pushing it in and getting it up to the top of the valve body.. If the shaft is really cruddy, you can clean it with some steel wool or something like that. Now put the packing nut back on and screw it back down. Put the handle back on. "Tight enough" for the packing is when the valve is showing some resistance to turning beyond what it had when you started… if it still drips, tighten the packing nut a little more.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1846204#Comment_1846204

Here you go.

https://youtu.be/Tb7RYE4KOXk?feature=shared

Jamie Hall

Thank you!