service valves in central heating system

[AJ16]

I want to isolate the heating system at one end of the house and have fitted two service valves into the 15mm flow and return, just wondering if this is ok. There are 4 rads that are isolated. The valves restrict the flow a bit but will this be a problem when the valves are opened again to switch the rads back on? What I'm really asking is if it's strictly necessary to use the lever type valves which keep a 15mm bore when open? Thanks AJ

 

[REDSAW]

I want to isolate the heating system at one end of the house and have fitted two service valves into the 15mm flow and return, just wondering if this is ok. There are 4 rads that are isolated. The valves restrict the flow a bit but will this be a problem when the valves are opened again to switch the rads back on? What I'm really asking is if it's strictly necessary to use the lever type valves which keep a 15mm bore when open? Thanks AJ

i have done this a few times, although sometimes frowned upon but hey, if you have too and it makes sense!.
it is no different than micro bore, but after a while they may block up the ball valve. just use ordinary iso's there neater.

 

[Phil]

I've done it once, a few years ago when I was a diyer.

Its not really the thing to do but if you must do it then use full bore as you dont want that bottleneck 'balancing' your system for you and encouraging the water to turn round and heat another rad instead.

If depends on the size and layout of the system though.

 

[AJ16]

ok thanks, I guess what I could do is to replace the service vales with compression straight connectors once the work is completed on the isolated section then there surely wouldn't be any probs with restricting the flow??

AJ

 

[PlumbBobBob]

the only problem being compression straight connectors are shorter than iso valves.

 

[AJ16]

is it possible to get longer length connectors?

 

[stevetheplumber]

is it possible to get longer length connectors?

yes they are called repair couplings

 

[radswilldo]

You can get full bore ball-o-fixs now(slotted).

 

[AJ16]

nice one, I just found them on the Toolstation website.
AJ

BOFs look better still, Screwfix have them I see.
Cheers for that

 

[REDSAW]

You can get full bore ball-o-fixs now(slotted).

where?
toolstation don't do them/.

 

[AJ16]

that's right it was the repair connectors I saw on TS, the full bore valves are a Screwfix

Screwfix have the full bore valves

 

[Robtheplumb]

Toolstation do do them

Toolstation

 

[stevetheplumber]

I want to isolate the heating system at one end of the house and have fitted two service valves into the 15mm flow and return, just wondering if this is ok. There are 4 rads that are isolated. The valves restrict the flow a bit but will this be a problem when the valves are opened again to switch the rads back on? What I'm really asking is if it's strictly necessary to use the lever type valves which keep a 15mm bore when open? Thanks AJ

i used to do this but most of the ballofix valves you get now are so poor quality i found they will start leak from the screw in a short time so best to use gate valves
i still dont leave them on if they are going to be inaccesable under laminate or similar

 

[AJ16]

well spotted thanks

good point. Are gate valves say from Toolstation or Screwfix gauranteed to be any better than a full bore valve?

 

[radswilldo]

I wouldn't buy fittings from screwfix, I've seen whole bags of fittings that have not been totally deburred, copper fittings that will not fit on copper pipe, etc. Buy from a plumbing yard, the ball-o-fixs I use have no problems and are more expensive than those sold by on-line companies, not by much, but are better in quality. Use the fullbore ones, just give the slots a few turn before connecting.

 

[AJ16]

I got some full bore valves with wing nut type handles on from PTS this morning, the quality looks good. Thanks for all your comments. AJ

 

[REDSAW]

Toolstation do do them

Toolstation

ohh arr
couldnt find in catlouge tho ta.