Adding a new radiator. Easy???

[GazNicki]

Hi all,

We would like to add a new radiator to our living room. The house is a semi which is over 130yrs old so has nice high ceilings, but there aren't enough rads on the rooms to warm the house and in the winter we get mould and mildew problems, particularly on external walls where radiators are not present.

Let me start by saying I know Jack about plumbing, but willing to learn and try. Also, affording a professional plumber is out of the question at the moment.

We have a cellar, and by going down and having a look I can see the following:

There is a thick (guessing at 25mm) copper pipe on the underside of the floorboards. From this two 15mm (I assume) pipes feed a radiator in the hallway (internal wall which divides our house from the next).

From this, two push fit connectors are joined in which feed the radiator in the living room, again against an internal wall.

I want to fit a 300mm x 800mm radiator to the wall under the window. This wall it notoriously cold and one which gives mould/mildew problems.

I have checked my boiler (Ideal Isar HE24) and this has an output of 23.4kW (max). I converted this to BTU and got over 78,000 BTU/hr. I measured the existing rads and used an online retailer to get rough estimates on the BTU they put out and deducted that from the boilers max output and I have 38,000 BTU to play with.

My proposed radiator will put out no more than 3600 BTU.

Firstly, am I working this out right or am I getting it all wrong.

Secondly, is it just a case of draining the system, fitting the rad to the wall, and using the same white plastic piping which feeds the living room radiator to t-in and feed the new rad - then sitting back and have the wife tell me how clever and manly I am?

Any advice greatly appreciated.

 

[Armo74]

Firstly you need to work out the heatloss from that room properly that will then tell you how much heat you need to heat that room you can then choose the right radiator with the correct heat output.
You can't just put any old size in these things have to be worked out properly otherwise you will be disappointed with the room temperature and the only comments your wife will be giving is how cold it is in that room.
You also need to plan the pipe runs ideally the runs to the new radiator should come from the main flow and return pipes.

 

[PrenticeBoyofDerry]

To size the radiator you require, ideally you need to do some heat loss and ventilation loss calculations. You will need to find out the u-values of the fabric of the room.
I personally would be considering, insulating the property more efficiently.
It's okay saying you cannot afford a plumber and i have nothing against a man or woman wanting to get there hands dirty and gain a little knowledge at the same.
But if it's purely down to finances, if you have not got any knowledge and likely no professional tools and equipment, it is very likely a false economy DIYing.

 

[buck51]

if you think its going to be easy search this forum for problems with new rad, you will be amazed at the problems people have with such a simple job so do some reading and dont fall into the same traps as them

 

[Agile]

I would say that its a very simple task!

But there is a concurrent thread where a professional plumber has fitted a new rad and it does not work.

He even suggested that the new rad valves were faulty!

Tony

 

[buck51]

But agile only repairs boilers because he cant carry big radiators on the bus

 

[Galoka]

Well, yes, really you should do a heat loss calc, have a look at this page which explains it, it's not as bad as it looks

http://wiki.diyfaq.org.uk/index.php?title=Heat_loss

You avoid then doing the work and getting it wrong, and it not being warm enough.

However, you can always just do it and cross your fingers. Put a TRV on the rad anyway.

Plastic pipe would certainly be the way to go for you. A few pointers though. Try to take a new feed frm the 22mm pipe.

Polybutylene pipe is more flexible, but comes in big rolls. as your runs sound fairly simple, you can probably use straight lengths of PEX pipe - usually 3m lengths. Use the proper inserts, should really use the proper cutters for plastic pipe - not expensive. But I've done some joints with a stanley knife, but you need to take care to get a straight clean cut. Not too bad if you can sit with pipe on a nice firm surface in front of you but not good when trying to do the cut under the floor or whatever.

A little cutter for the 22mm pipe is much easier than a hacksaw - though again can be done, but take care to make sure you tidy it up well afterwards. Use copper pipe for the drops from the rad under the floor, looks much better.

Check the construction of the wall for the rad. We had lathe and plaster bay walls in our 1930's semi, which made hanging rads fun.

Put in inhibitor when you fill up.

Enjoy your warm room and yuor wife's adulation