Do you recognise this TRV. Also, pump issues.

[bodgeitandsee]

Hi,

Further to an earlier similar thread I hope someone can help resolve my CH issues.

To start with does anyone recognise the TRV below and if so do you know how to get the TRV head off?

Further to the rest of my original post, below, could it be these TRV's that are only allowing my rads to heat up at the top?

After increasing flow on bathroom rad via lockshield it heated thoroughly which makes me question if it is sludge in the rads. Some of end rads already have lockshields on max and are nearly cold so solution must be elsewhere.

Also further to original post, could my pump problem be the cold feed that crops up so often as a potential remedy? When I drained and refilled the system it filled perfectly so I suspect the cold feed must be OK but advice from the pros would be great.

The pump is normally barely discernable from the lounge but occasionally sounds as though it steps up a gear with slight thumping for a min or 2 and a bit of a whooshing sound. As stated below, this happens with the boiler running continuously so it's not being switched as it's wired with the boiler (Ideal W RS450)


Thanks




Original post......................................


Hi

Already posted for help after having a boiler airlock which is now OK.
I have a 30 year old system (fully pumped - vented CH) with a 17 year old boiler and suffer cold bottom rads (2 x 2200mm double each with saucer sized warm areas in top corners and that's it, all others as bad).

Currently running a litre of Fernox Heavy Duty Restorer to try and sort it.
All TRV's (ancient MMA ((??)) looks like a joined up logo on valve body not TRV cap, can post a pic if needed) all set to max.

Could it be that the pump is losing it's efficiency - Grundfos 15-50, it is in the loft above the lounge and sometimes sounds as though it steps up a gear, this happens even during a boiler continuously on period so it's not switching.

I have just opened the lockshield on the bathroom rad by three quarters of a turn and the bottom of the rad is now hot which makes me think it's a criculation problem.

Also the furthest rad from pump has it's LSV fully open and barely loses it's chill. Can't turn down any earlier ones because they're not warm enough themselves.

The pump sounds were happening prior to drain and refill so it's nothing that I've caused. Would also say the system water looked fairly clear when drained, certainly not sludgy.

Any ideas how to get the caps off these decrepid old TRV's?

Thanks for any help.

 

[bripl]

pictures not very clear but i think it is a old danfoss

 

[Trev B]

They're that old even Noah refused to have em on the arc......

Almost certainly th pin inside is stuck down inside the TRV restricting the flow, undo the big nut below the white plastic ander the grey head, pull the head off and try to release the pin underneath with a pair of plyers or tap it lightly with a hammer, but be careful because the pin may come out and release water, don't panic just stick it back in if it does, but if the pin springs back up and has a spring resistance to it when you push it down with a srewdriver or similar then it should let water by, see how the radiator fairs after that, leave the head off if you have to but ultimately all the TRV's need changing but beware those ones you have are meant for steel pipework adapted for copper which makes their pattern quite big and more modern patterns are smaller which may mean you need to alter a little pipework on some,

hope this helps, Regards, Trev.....

 

[JohnD]

I've got a lot like that, I think I got them as B&Q own-brand. i think the blue logo says MA

 

[PIPERPETE]

You cannot remoe the head on these older models, Buy new sunvic or danfoss heads, remember if you have a fairly recent boiler make sure that you have a by pass fitted if you are using a lot of trv's

 

[JohnD]

You can take the tops off mine as Trev described, they came with screw-down plastic caps that push the pin if you have removed the thermo heads e.g. for decorating.

 

[bodgeitandsee]

PiperPete,

I'm going to change them all for drayton TRV 4's when I get to it but looking for confirmation I have circulation really at the moment.

So you think it unlikey that the head will even come off these?

I have 2 rads without TRV's at moment to provide the free flow, this will be reduced to one soon when I move the room stat to the hall (currently in south facing lounge which gets heated by the sun).

When I get a new boiler next year I'm thinking of going fully TRV with bypass valve fitted if the boiler requires it.

 

[JohnD]

So you think it unlikey that the head will even come off these?

the heads come off mine, and they look the same as yours.

 

[bodgeitandsee]

Thanks JohnD and Trevor.

I'd contemplated undoing that nut but didn't fancy a soaking unless I knew it was the head release.

Have taken the head of one of the coldest and the pin has around 3mm of movement and returns fine. Would this be an indication it's working OK?

Rad not getting any warmer yet but I'll leave it off for a while.

 

[JohnD]

let me see if I understand this sludge thing.

(1) Is the rad only hot at the top and the incoming tap?

(2) Or is heat travelling down to the outlet tap but leaving the middle/bottom of the rad cold?

 

[bodgeitandsee]

JohnD_

Both top corners are heating but the cold area is a full pyramid from bottom corners to practically top middle.

One 2200mm rad has no more than an A4 size hot area in each top corner.

The same was true in the bathroom untill I opened the lockshield by a turn and it heated fully. Problem is that other rads are already fully open but cold.

Think I'll try a new pump.

SORRY to mod and whoever as it seems my two threads are combining onto a similar topic line although the other started on a specific pump question.

 

[JohnD]

Try turning off all the rads except one and see if that one gets thoroughly hot.

Do it to each rad in turn.

If they all do, it sounds like a flow prob.

Have you got a 3-port valve? They often fail to direct the water properly, then it all takes the easy route through the HW cylinder.



p.s. by directing all the flow through a single rad you give it more chance to dislodge any muck. Draw off a bit from the drain and see if it's still clear (you can put it back (less any sediment) into the header tank to avoid losing cleaning fluid.)

 

[bodgeitandsee]

I've got 2 x 2 port valves

 

[JohnD]

Beyond my limits. But can you feel the pipes and see it the HW seems to be getting a lot?

 

[bodgeitandsee]

With DHW on or off I'd say the CH pipe from zone valve was hot but no expert to say if it's hot enough. The zone valves are certainly doing their duty anyway.

I know I'm very inexpert but gut feeling tells me to change pump on basis I think this one is getting on a bit anyway.