micro bore CH question - manifolds and adding a radiator

[AlF2008]

hi folks

I'm looking for a little advice on a micro bore CH system. We've recently moved into a old (1930's) bungalow, the heating system is reasonably old but still functioning well. Boiler will be replaced at some point in the near future but for now the plan is to move and replace an existing radiator for a physically smaller one (due to size constraints) and possibly adding another small radiator should this not be sufficient. I've been reading up on heating systems in general and the system looks like this:

http://www.diydata.com/planning/central_heating/pipework.php#microbore

At the moment there is a single manifold going from 22mm to 6x8mm to feed the 6 radiators in the house. The manifold looks like a bigger version of this:

http://www.toolstation.com/images/library/stock/webbig/12184.jpg


Moving the radiator isn't a problem and I'm happy with doing that.
If I need to add a radiator whats the best way to do it? I dont want add it in series as the pipes are fairly long already. I was thinking of removing the existing manifold, branching the 22m into 2 and then adding 2 new manifolds to feed 4 and 3 radiators respectively. this is mainly as I cant find any manifolds for 6 or more except for use with under floor heating although I've not had a lot of time to investigate. Is that the best idea? If not then what is the alternative.

Longer term the entire system is going to be replaced so I dont want to go crazy with ripping out large parts of it just for this.

Thanks in advance
Al

 

[wiggikins]

Iagree with y our proposal, best way to go about it, cap any unrequired feeds/returns at manifolds and don't forget inhibitor on completion!

Keith.

 

[AlF2008]

thanks for the reply Keith.

Any suggestions for a supplier for manifolds with compression fittings? Majority of the manifolds I can find online appear to be pushfit which isn't something I've used before. I guess I could always give them a try though...

 

[mikej2005]

thanks for the reply Keith.

Any suggestions for a supplier for manifolds with compression fittings?

I managed to get hold of 2 manifolds last year that went from 22mm down to 4x10mm. The 22mm passed through, allowing the run to continue or the addition of a 5th 10mm outlet with suitable reducers.

The 22mm outlets were end-feed and the 10mm outlets were compression.

I did have to trawl the plumbers merchants for these though and think I got the last two in stock. Plastic seemed to be the way they were all going. (I've also used a 22mm x (4x15mm) SpeedFit manifold elsewhere on the system and that seems to be fine)

 

[Agile]

There is no requirement to use a manifold! That was just to make it simple for DIYers.

You can make up a manifold from 15 mm tees with a reducer and feed them from a 15 x 22 x 15 mm tee .

Far cheaper that way.

If you just want to add another circuit or two just use a tee off the 22 mm feed and return to add the extra ones leaving the existing manifold in place.

Tony

 

[AlF2008]

Well if nothing else it would help keep it tidy!

I'm going to look into draining the system at the weekend along with extending the existing pipes for the new radiator.

It the new radiator isn't enough to heat the room then I'll need to rethink the plumbing.

Edit - didn't see the last bit of tony's post.

 

[Agile]

Radiators are rarely oversized!

Dont expect a smaller radiator to be adequate in the coldest weather!

You may manage depending on what the room is used for. Perhaps by adding electric heating on cold days.

If its significantly smaller then I would advise you add a second radiator at the outset.

Tony

 

[AlF2008]

Radiators are rarely oversized!

Dont expect a smaller radiator to be adequate in the coldest weather!

You may manage depending on what the room is used for. Perhaps by adding electric heating on cold days.

If its significantly smaller then I would advise you add a second radiator at the outset.

Tony

Due to the relocation I've got to use a smaller radiator. I was expecting the modern double radiator to give out more heat than a older one. I'll need to check the size of the existing one when I get home but I susect its about 1200 x 600mm (double). The new one is going to be a double 1000 x 600mm.

The room is going to be the master bedroom and is reasonably warm at the moment despite having no floor covering and some reasonable sized holes in the skirting boards. Hence why I think the replacement should be sufficient. I'll measure up tonight.

I'm also planning on adding TRVs to all radiators at the same time too.

 

[Agile]

Thats not so bad, just about 18% less heat output.

However, if the old one is NOT finned then your finned replacement could even have a little more output.


Tony

 

[AlF2008]

I was trying to find a picture of something similar. This is the best I could find. Its a double version of the one pictured in the first post here:

//www.diynot.com/forums/viewtopic.php?p=675505

(I suspects its pretty old)

 

[Agile]

Its irrelevant what the old one looks like!

Its just a question of whether it has fins or not!

Tony

 

[AlF2008]

I presumed that ones from a certain era might be more/less likely to have fins hence the link to something similar.

Anyway now that I'm home, I can confirm that the existing one does not have any fins and is 1400mm long. Any idea what rough output it would have?