Replacing Radiators before boiler replacement

savings37

Richard1212 said:

According to a BBC article I've just been reading, you can throw away your radiators---the future is : 

Electrically heated wall paper   

Oh I hope so, I'd rather wallpaper than plumb any day 😁

ComicGeek

Richard1212 said:

According to a BBC article I've just been reading, you can throw away your radiators---the future is : 

Electrically heated wall paper   

At least that article pointed out the massive running costs associated with it compared to gas boilers. Most seem to gloss over that inconvenient truth.

FreeBear

ComicGeek said:

Richard1212 said:

According to a BBC article I've just been reading, you can throw away your radiators---the future is : 

Electrically heated wall paper   

At least that article pointed out the massive running costs associated with it compared to gas boilers. Most seem to gloss over that inconvenient truth.

Also no mention of what dangers are lurking should you wish to hammer in a nail to hang a picture or put up a shelf. Someone is going to be in for a bit of a shock methinks.

BUFF

savings37 said:

All excellent tips thank you, yes I'll be fitting TRV's on all rads. 

I have measured for new rads and yes I'll have to go slightly shorter and use valve tail extensions.

I've been using an online room size calculator to calculate for the required rad BTU size. I'm also trying to not get rads that come away from the wall too far which will require further pipe work. It's a bit of a balancing act.

When oversizing rads do you mean fitting a 21 or 22 in place of an 11 type? 

I would be using Delta T 30 output values & pick width/height/type accordingly for each to give that required value for each space.
Unlike FreeBear I don't have an issue with a type 22 sticking out ~100mm from a wall rather than ~75mm for a type 21 but it is your house so you decide what suits you.

ThisIsWeird

The upsizing isn't just about making your new boiler work more efficiently, but future-proofing the rads to work off heat pumps, and other low temp output devices.

FreeBear

BUFF said: Unlike FreeBear I don't have an issue with a type 22 sticking out ~100mm from a wall rather than ~75mm for a type 21 but it is your house so you decide what suits you.

A bit more than that I'm afraid. Looking at the Kudox guide, a Type 11 projects from the wall 85mm. Type 21 is 101mm, and the Type 22 is 135mm. If you go silly and opt for a Typ 33, the projection is 181mm.

I'm going to have a Type 22 in my lounge as the equivalent Type 21 in heat output is just way too big for the wall.

ThisIsWeird

Another option is to have an additional rad for the extra output. Chosen carefully, they could fit in better than one bigger rad. We've a couple of matching, anthracite-colour, column rads mounted on opposite walls, and I think they actually add to the room's aesths.

savings37

What's the general opinion about carrying the work out over say 2 weekends, this would mean draining the system twice and running it in between weekends, is that detrimental to the new radiators.

On the plus side I'd check for leaks on half the rads in-between weekends

ThisIsWeird

savings37 said:

What's the general opinion about carrying the work out over say 2 weekends, this would mean draining the system twice and running it in between weekends, is that detrimental to the new radiators.

On the plus side I'd check for leaks on half the rads in-between weekends

No issue at all. You'd have a bit more 'bleeding' to do, as the fresh water will have a fair amount of dissolved air in it, but that ain't a biggie. But no corrosion or other issue in such a short period - I wouldn't bother adding inhibitor for just a few weeks, for example.

BUFF

FreeBear said:

BUFF said: Unlike FreeBear I don't have an issue with a type 22 sticking out ~100mm from a wall rather than ~75mm for a type 21 but it is your house so you decide what suits you.

A bit more than that I'm afraid. Looking at the Kudox guide, a Type 11 projects from the wall 85mm. Type 21 is 101mm, and the Type 22 is 135mm. If you go silly and opt for a Typ 33, the projection is 181mm.

I'm going to have a Type 22 in my lounge as the equivalent Type 21 in heat output is just way too big for the wall.

Fair comment, the standard bracket typically adds ~25-30mm. 
However, still for me the wall space (w x h) taken up is of more concern than the depth.