Adding Radiator To Existing Feed/Return Pipes?

[Ripperoo]

Hey guys

First things first, Happy New Year to you all.

What I'd like to know is whether it's possible to tee off from the feed and return pipes of an existing radiator and add an additional radiator?

I'm guessing it's probably not advisable, but thought I'd better ask first.

When the central heating was fitted years ago, no radiator was fitted in the rear hall and because of this, it gets very chilly.

It actually feels like the heat from the lounge is being sucked out when a door is opened into the rear hall.

What I'm proposing is to add an equal tee compression fitting to both the feed and return pipes, connecting each to a separate radiator.

The additional radiator will be fitted on the other side of the wall from the existing kitchen radiator (new pipes will be fed through the wall to new radiator).

The current system is a Baxi Bermuda, running on 8mm microbore and currently supplying 6 radiators all with TRVs except the one the bottom of the stairs where the stat is located.

My guess is that it won't work properly and if this is the case, is there any other alternative that doesn't require major upheaval with regards lifting carpets, floorboards etc?

Cheers.

 

[Whitespirit66]

Unless the existing kitchen radiator is small, and the new rad will be small, you are limited to the heat carrying capacity of 8mm pipe. Ideally you would take a new 8mm microbore flow and return back to the manifold.

What size will the rads be?

 

[Ripperoo]

Unless the existing kitchen radiator is small, and the new rad will be small, you are limited to the heat carrying capacity of 8mm pipe. Ideally you would take a new 8mm microbore flow and return back to the manifold.

What size will the rads be?

Existing radiator is 700x600mm 'Quinn Barlow - Q22706RT - Round Top' double convector, which has a BTU of 4462.

New radiator will be 700x600mm 'Quinn Barlow - Q11706RT - Round Top' single convector, which has a BTU of 2474.

Rear hall is quite small, being approx 3m x 1m, but has downstairs WC and understairs cupboard (originally pantry/cold store), which have no radiators themselves.

The outside wall of the WC and understairs cupboard is the tunnel between two terraced houses, which in itself creates a cold spot, so hopefully if the above mentioned radiators are OK, some heat might drift into these areas to eliminate any cold spots.

Can't really run a pipe back to the manifold as this is situated under one of the bedroom floors and had new carpets fitted recently and I'm pretty sure from memory that all available outlets were used, but on saying that, I may be wrong because I can't imaging a manifold having seven outlets.

I have read another thread on the same subject, which said it can be done, but not recommended if radiator total more then 6000 BTU on 8mm microbore. Mine will total 6936 BTU)

 

[Whitespirit66]

Those BTU totals take you up to the maximum for 8mm, so will just about be OK. Will need to rebalance system after installation.

 

[Ripperoo]

Thanks Whitespirit66

Those BTU totals take you up to the maximum for 8mm, so will just about be OK. Will need to rebalance system after installation.

Great, so it's considered OK to tee-off from an existing feed/return then?

That's great.

As the only way to the additional radiator will be to drill directly through the wall, is there a preferred method?

Or is it just a case of drilling perhaps a 10mm hole and filling in around the pipework where necessary?

Regarding the balancing of the system, will this DIY NOT GUIDE be ok?

I've just ordered a Ryobi RP4030 Infrared Thermometer, will that be suitable?

If not, any recommendations for suitable thermometers to check in and out temps?

Thanks again for all your advice WhiteSpirit66

 

[Whitespirit66]

Oversize the hole, and sleeve the microbore in a bit of plastic pipe, or the masonary/cement will corrode the copper.

You can buy copper microbore from some merchants or Ebay by the metre if you only need a small amount. Saves having to buy a whole coil of it.

 

[Whitespirit66]

Regarding the balancing of the system, will this DIY NOT GUIDE be ok?

Will be slightly different, because unlike other systems, rads on manifolds heat up at the same time. The bit about finding out which rads heat up first won't apply so much to your set up.

It's all about balancing the resistance between different rads in the system. The two rads on one feed will have greater flow resistance than other rads that have their own dedicated feed. To even things up, you need to give the rads with their own feeds greater resistance by closiing down their lockshield valves.

I would try with the 2 rads l/s valves fully open and all other rads only quarter or half turn open. You can then fine tune to get them right. Bigger rads may need to be open more and vice versa. Not a big system, so shouldn't be too bad

 

[Ripperoo]

Oversize the hole, and sleeve the microbore in a bit of plastic pipe, or the masonary/cement will corrode the copper.

You can buy copper microbore from some merchants or Ebay by the metre if you only need a small amount. Saves having to buy a whole coil of it.

I was actually wondering about sleeving it to be honest, but didn't ask in case it was considered a dumb question. LOL

Already got some microbore from a previous job (whole coil), but again, thanks for the advice, it is greatly appreciated.

I've just ordered a RYOBI RP4030 Infrared Thermometer, will that be suitable?

If not, any recommendations for suitable thermometers to check in and out temps?

 

[Ripperoo]

Regarding the balancing of the system, will this DIY NOT GUIDE be ok?

Will be slightly different, because unlike other systems, rads on manifolds heat up at the same time. The bit about finding out which rads heat up first won't apply so much to your set up.

It's all about balancing the resistance between different rads in the system. The two rads on one feed will have greater flow resistance than other rads that have their own dedicated feed. To even things up, you need to give the rads with their own feeds greater resistance by closiing down their lockshield valves.

I would try with the 2 rads l/s valves fully open and all other rads only quarter or half turn open. You can then fine tune to get them right. Bigger rads may need to be open more and vice versa. Not a big system, so shouldn't be too bad

Great stuff!

Thanks for that whitespirit66.

 

[Whitespirit66]

I don't get too hung up about exact temps. Do it more by feel. If the rad heats up evenly all over, job's a good 'un.

No experience of this thermometer. Looks the biz though. I've just got some low-tech clip ons gathering dust somewhere.

Good luck!

 

[Ripperoo]

I don't get too hung up about exact temps. Do it more by feel. If the rad heats up evenly all over, job's a good 'un.

No experience of this thermometer. Looks the biz though. I've just got some low-tech clip ons gathering dust somewhere.

Good luck!

One more thing, Does it matter which way the equal tee joints are connected.

Or does the the feed pipe need to enter the centre connection of the equal tee, so as to 'split' the hot water to the outlets on opposite ends of the coupling.

Also do both return pipes need to enter the equal tee at opposite ends of the coupling, so that both return pipes 'mix' into the centre connection before returning to the boiler?

I hope you can make sense of that gibberish.

Also, maybe that thermometer is a bit of overkil then? LOL

 

[Whitespirit66]

You can connect the tees any way, the flow through them will be pushed or pulled by the pump.

I'm sure the thermometer will have it's uses.

 

[Ripperoo]

You can connect the tees any way, the flow through them will be pushed or pulled by the pump.

I'm sure the thermometer will have it's uses.

Great stuff!

Thanks for all your advice and best wishes for 2013.

 

[Nige F]

My tuppenceworth If you`ve got a load of pipe going spare - locate the manifold - it might have a set of spare tappings then pipe the rad from there . I`m doubtful about old , maybe sludged microbore being up to it`s ( technical ) max - either way you`ve little to loose

 

[Ripperoo]

My tuppenceworth If you`ve got a load of pipe going spare - locate the manifold - it might have a set of spare tappings then pipe the rad from there . I`m doubtful about old , maybe sludged microbore being up to it`s ( technical ) max - either way you`ve little to loose

Thanks for the advice Nige F, but I don't think I'd have enough microbore for two runs of pipe back to the manifold anyway (manifold is about 10 meters from radiator).

When I said whole coil, earlier in the thread, well it was before the 'Last Job', but there's only about 10 metres left.

Besides, from memory, I don't recall seeing any spare tappings and to be perfectly honest I don't wanna really have to lift the recently fitted carpets and floorboards.

I'm not too fussed whether I get a lot of heat in the rear hall, just so long as it takes that chill away.

Thanks again guys, your advice is really appreciated.