Adding a radiator

[focaltucker]

I am looking to add a new towel warmer to my bathroom and wanted to check if there's something I need to be aware of.

There is a small rad in the bathroom on the opposite side, which I want to remove and cap off. My first query is if it's OK to do this using the 10mm pushfit end caps or should I be using something more permanent? I want to avoid soldering.

I have a combi boiler and the main flow and return pipework across my landing is 15mm and it T's off into 10 mm for the rads. I want to T into the 15mm and run 15mm pushfit through to the new towel warmer. Would using the pushfit T's be OK on the existing copper, or would it be a better job to use the compression spanner type T's, then a small piece of copper pipe and convert to plastic from there?

I intend draining the upstairs rads first via the drain on the boiler and opening the bleed valves.

I am not sure why the main flow and return is 15mm pipe and not 22, as this feeds 4 rads?

However, will using a new 15mm run of about 3metres to the towel warmer, mid way through the run adversely affect the two later rads or should they be OK if the rads are balanced up?

When I refill the system after the work, is there anything I need to do other than fill, bleed and fill again to 1 bar?

 

[Softus]

My first query is if it's OK to do this using the 10mm pushfit end caps or should I be using something more permanent?

Something less able to come off without the use of tools.

I want to avoid soldering.

In that case a compression stop end would suit your needs just perfec'.

Would using the pushfit T's be OK on the existing copper, or would it be a better job to use the compression spanner type T's, then a small piece of copper pipe and convert to plastic from there?

On old copper I wouldn't use plastic pushfit - compression would be wiser. However, you can use plastic pipe straight into the compression tee. Just make sure you use the manufacturer's inserts for the plastic pipe.

I am not sure why the main flow and return is 15mm pipe and not 22, as this feeds 4 rads?

Because someone has been lazy, or short-sighted, or incompetent.

However, will using a new 15mm run of about 3metres to the towel warmer, mid way through the run adversely affect the two later rads or should they be OK if the rads are balanced up?

You don't have much to lose by trying it out - you can always change the 15mm distribution pipework later if you want to.

When I refill the system after the work, is there anything I need to do other than fill, bleed and fill again to 1 bar?

Yes. You need to add a dose of chemical corrosion inhibitor. It would be wise to renew the DOC washer before filling.

 

[focaltucker]

Many thanks for that. I will get some compression T's and 10mm stops.

I am not sure why the main flow and return is 15mm pipe and not 22, as this feeds 4 rads?

Because someone has been lazy, or short-sighted, or incompetent.



The CH was fitted before I bought the house 10 years ago, but according to the docs it was British Gas and therefore probably quite expensive. Surprising that they have seemingly cut corners. How many Rads should be fed by a 15mm supply?

They have also just grooved into the top of the joists, so they sit right under the floor.

 

[focaltucker]

Forgot to check - how / where do I add the corrusion inhibitor and what's the DOC washer?

The boiler is only 2 years old if it's part of the boiler itself.

 

[Softus]

How many Rads should be fed by a 15mm supply?

That depends on the sum of the heat output from the rads.

They have also just grooved into the top of the joists, so they sit right under the floor.

That's poor show; a crime against common sense, apart from anything else.

Forgot to check - how / where do I add the corrusion inhibitor

In a closed system it's usual to inject it into a rad vent plug hole. If you buy the appropriate product it will come with some adaptors for doing just that.

and what's the DOC washer?

A washer that stops water from coming out of the spout of a drain off cock.

 

[focaltucker]

Thanks. I will look for some corrosion stuff.

Rad wise I have two doubles, one 800 x 600 and one 1000 x600 and 2 singles, one 1400 x 700 and one 1000 x 500. I am adding a towel warmer of about 2200btu.

I'd look at going back further on the main pipework except it's under a laminet floor that would all need taking up.

Does it matter if the thermostatic valve goes on the flow or on the return feed?

 

[AlF2008]

depends what type you have. some can be fitted to either and others are for flow side only

 

[focaltucker]

It's a Drayton TRV4.