Thermostatic Radiator valve snapped help

[nursek]

The TRV head has snapped off our radiator, I have seen how to replace the head on YouTube etc but not sure whether the metal spindle is also broken
Can anyone assist?
Will the radiator leak when the heating is on? If so how do I stop it as a temporary fix?
Many thanks, see pictures

 

[martygturner]

TRV work by pressing down on a plunger valve - that's the bit sticking up from the middle the metal valve body. They do not require much force to open, a spring keeps the valve shut untill the TRV head expands and forces the plunger down... so as to leaks it won't leak anymore than it is - see the green goo which points to a small weep.

As the trv head the plastic bit can be bought on its own cheaply, its worth trying to get the valve body back into service, a good soak with white vinegar or viacal or wd40 etc to get rid of the crud. The vavles stick in the body and should move with just a bit of pressure from say a large flat screwdriver, tapping with a hammer can break up the crud in the body, but needs persaverance. Tap a few times , press down and repeat.

To replace the trv head you will need to dig out the remnants of the old one from the screw fitting it mounts to on the body

 

[nursek]

So it's just the valve head broken not the spindle you think?
Many thanks for the advice
Do I need to turn the radiator valve off on the other side of the radiator before attempting to change the TRV valve?

 

[Hugh Jaleak]

Metal pin into Valve that should move to control the flow of water is fine. Might be worth using the flat edge of a screwdriver just to apply gentle pressure to the pin to ascertain it moves fairly easily. If all ok, see if you can find a replacement head, (will need to remove remnants of old head and the metal disc that screws on to hold the head in place first.) This can be done without turning the water off. Take care though to support the Valve body whilst you work on it, you have Microbore pipework, wont take much to bend, kink or break that!

If you need to replace the entire Valve, that is the metal body as well, then you will need to isolate the supply to the heating system and drain down, otherwise you will find yourself very quickly in a mess. Again, you are dealing with Microbore so will need a suitably size valve or reducing set to replace the existing, and care must be taken not to damage the pipework.

 

[ericmark]

There are a few threads, but most electronic heads come with a few options and will auto adjust to your valve. I have fitted 5 of these in 2019 they were £15 each, there are others I have a Kasa, Draytion Wiser, and Energenie, but the eQ-3 shown and Terrier i30 do not need a hub, and seems silly to replace with non-programmable type.

 

[CountryFan]

Existing looks like a Myson if you’re unsure.

 

[flameport]

Will the radiator leak when the heating is on?

If it was going to leak it would already be leaking.
The water is in there all the time, it doesn't disappear when the heating is off.

 

[foxhole]

Try and buy same brand as failed unit , threads on trv valves can vary .

 

[ericmark]

Try and buy same brand as failed unit , threads on trv valves can vary .

Yes, think 30 mm and 32 mm, with mechanical valve heads, there are no adaptors with the new head, with electronic valve heads, normally there is a pack of adaptors with the head, and with the wiser you can send for more free of charge.

It does vary a little, the Energenie came with both 30 and 32 mm options, but it does not report if the stroke is within limits, the eQ-3 however, shows if jammed, over or under, can't remember about Kasa and Wiser. Not only the threads can change, but also the stroke, and the electronic auto adjust to suit the valve, the mechanical doesn't have that function.

Set to 2.5 with a scale of * 1 2 3 4 5 6, the mechanical valve will start to close at around 18ºC and not fully close until around 22ºC what I would call near enough engineering, but the electronic set at 20ºC and starts to close around 19.5ºC and fully closed at 20.5ºC so far more accurate, plus it can be programmed for different temperatures through the day, and exercises the valve once a week, so all in all a far better option.

The Terrier i30 is local setting only, the eQ-3 has both local only and bluetooth, the latter allows two radiators in the same room to be linked, so both open together, the Kasa, and Energenie connect to hubs, (which in turn connect to internet) but Kasa can be still manually set, the Energenie you can't set without the hub, the Drayton Wiser connects to a hub which controls the heating, so the TRV head can fire up the boiler.

My last house, open plan, only needed TRV's in the bedrooms, a single wall thermostat in the arch between the two main rooms, controlled the whole house, but this house has the old fashion idea of doors on every room, so no need to heat rooms which are not being used to same temperature as those being used, and the 10 programmable TRV heads save me a lot of money turning on rooms only when required. They have also helped to set the lock shield valves, and rooms are normally within 1ºC of what has been set, I will admit the Wiser linked TRV was maybe a mistake, the radiator is against a North facing outside wall, so it can start the boiler too early, once heating is running heart of winter no problem, the radiator causes a flow of air in the room, so the TRV is in ideal place to monitor whole room, it is Autumn and Spring when heating not active, when there is a small problem, and it can start boiler when not required, hindsight is good, where radiators are on an outside wall, room thermostats can be a better option on the opposite wall (internal) this is something the books seem to miss, if the radiator is on an internal wall, then a TRV will work better than a wall thermostat to trigger boiler, as in this case the wall thermostat would be on an outside wall.

 

[fixitflav]

a spring keeps the valve shut untill the TRV head expands and forces the plunger down

I think that's the wrong way round. If the head is off the plunger rises fully and the valve is wide open. The head pushes it down and reduces flow