Replacing 35+ year old radiators

[qwertyb]

I need to replace some 35+ year old radiators, sizes below, and I’d like to pick your collective brains.

Length Height Pipes c to c

1440(Double) 700 1520

800(Double) 700 870

640 540 720

965 700 1045

640 700 720

960 700 1050

960 700 1050

800 700 890


I’ve been looking at Kudox Premium radiators and assume that if I replace the doubles with double + single convector and singles with single + convector, I could probably get away with 600mm high radiators. Thoughts?

Next question is mounting. The walls are stud and plasterboard and I’m doubtful if I’ll be able to hit studs for most of the radiators. Is plating the wall with a sheet of MDF or ply the best solution and what anchors would you recommend?

The pipework is 8mm so I don’t seem to have much choice for TRVs. Danfoss RAS –C2 ok?

I also need to replace two Honeywell V4043H zone valves. Drayton ZA%/679-2 is much cheaper. Any difference in quality? The removable head on the Drayton sounds like an installation plus.

Thanks

 

[dilalio]

Do a heat loss calc for the rads.
Many sites have a sizing calculator that will help you... best heating etc.

Slightly oversize them as they can always be turned down.

You can get in valve reducers to take the pipe down to 8mm, so you can use any TRVs you want.

I'd consider getting rid of the 8 and going up to 15mm - hate all that small bore carp!

Honeywell MCVs all the time. Heads are removable and replaceable.

 

[dilalio]

35+ years old... 8mm???

 

[dilalio]

Mount using speed brollies or toggle bolts.

 

[qwertyb]

Thanks for the replies

Radiator sizing isn't a problem. I'd forgotten about tulips, so that could well be an easier solution than trying to get 8mm olives to bite on old pipework, and opens up a wider choice of valves. Changing all the pipework to 15mm isn't a viable option, and there's no problem with flow so seems like unnecessary expense and effort.

Main concern is hanging the radiators. Hanging 50kg or thereabouts on plasterboard with 4 brollies seems optimistic.

 

[dilalio]

Thanks for the replies

Radiator sizing isn't a problem. I'd forgotten about tulips, so that could well be an easier solution than trying to get 8mm olives to bite on old pipework, and opens up a wider choice of valves. Changing all the pipework to 15mm isn't a viable option, and there's no problem with flow so seems like unnecessary expense and effort.

Main concern is hanging the radiators. Hanging 50kg or thereabouts on plasterboard with 4 brollies seems optimistic.

It's a shear load, not cantilevered.
Brollies will be fine, or you can go for toggles/zip toggles/gripits or tear walls open and add timber grounds.
I'd go for brollies.

Still think 8mm is shyte... and how did that get there with 35+ y.o. rads ??

 

[Echo the husky]

The plasterboard is heavily bowed in my kitchen from having a double radiator hanging off of it, the radiator is leaning forward at a stupid angle. When I replace the board I'll be putting some timber between the uprights to fix it properly!

 

[dilalio]

The plasterboard is heavily bowed in my kitchen from having a double radiator hanging off of it, the radiator is leaning forward at a stupid angle. When I replace the board I'll be putting some timber between the uprights to fix it properly!

Then you must have very few studs!

 

[qwertyb]

It's not a pure shear load. To be pure shear, the line of action of the load would have to be vertical at the point of load, which it isn't due to the bracket being between the load and the load point.

Don't understand your attitude to 8mm. Explanation might be interesting.

The pipework's the same age as the radiators. It was built that way in 1981.

Bowing, as experienced by Echo the husky, or worse, is what I'm trying to avoid.

 

[dilalio]

My attitude! Don't like that comment.

Do what you will sir... you asked for opinions... mine come from experience.

Good luck in your endeavours.

 

[qwertyb]

Well that's a strange comment! Attitude - a settled way of thinking or feeling about something - which seems to reflect your comments regarding 8mm.

"Don't understand your attitude to 8mm. Explanation might be interesting." - Surely that's a simple enough question to answer? What's so bad about 8mm?

 

[Terrywookfit]

Still think 8mm is shyte... and how did that get there with 35+ y.o. rads ??

We used microbore for nearly all installs in the early 70's.
If sized and fitted properly there's nowt wrong with it......I refer to copper of course. not the plastic s hit with inserts reducing the bore to fook all !!

 

[dilalio]

Sizing and install is very important.
So is maintenance (perhaps more so).
Generally speaking, most occupiers don't even know what system water is, let alone about having it maintained.
Try power flushing an 8mm system having been tasked with getting it running again - its no fun when time/cost sensitive.

Only last week we had to sort out a blocked system on 10mm. Several rads hadn't worked for years. Big house, professional couple who asked "how can rads and pipes get blocked when they're filled with pure water???"

 

[Terrywookfit]

Sizing and install is very important.
So is maintenance (perhaps more so).
Generally speaking, most occupiers don't even know what system water is, let alone about having it maintained.
Try power flushing an 8mm system having been tasked with getting it running again - its no fun when time/cost sensitive.

Only last week we had to sort out a blocked system on 10mm. Several rads hadn't worked for years. Big house, professional couple who asked "how can rads and pipes get blocked when they're filled with pure water???"

I did say "If sized and fitted properly"........That includes the whole system !!!

I wouldn't attempt to flush blocked 8mm.

 

[dilalio]

I did say "If sized and fitted properly"........That includes the whole system !!!

I wouldn't attempt to flush blocked 8mm.

And I wouldn't dream of installing it.