Convector Radiators - frequently asked questions

Popular Questions

What are K1, P+, P2, K2 radiators?

K1 radiators refer to a single panel single convector radiator. Also known as type 11.

P+ referes to a radiator that has a a single panel with a single convector, type 21.

P2 is a radiator that has two panels and no convector fins. Commonly called type 20.

K2 radiators have two panels and each panel has a convector fin attached. These are also called type 22.

What is the difference between a radiator and a convector radiator?

Traditionally, hot water runs from the top down in a radiator, whereas in a convector radiator water circulates through tubing to heat the air. So while a normal radiator will push hot air out, a convector will cause heat to rise and circulate hot air more easily.

What does single convector radiator mean?

A single convector radiator is just a normal radiator that has one panel. Think of it simply as the tank which heats up the space you have it in.

What does double convector radiator mean?

Panels are the main surface (or tank) of the radiator and the convector fins are the zig-zagging strips of metal inside the radiator attached to the panel. A double panel radiator is a radiator which has a panel on either side with fins in the middle that give it that sandwich effect when you look down on the radiator.

How to choose the correct convector radiator - Be sure to check out our Pinterest and Instagram for inspiration

What size convector radiator do I need?

When selecting a convector radiator, you need to make sure it is the right size to adequately heat the room. Too small and your room won’t get hot enough, to large and the room will be too hot.

The easiest way to work out what you need is to use our Heat Calculator. You can put in the dimensions of your room and various other pieces of information and you will be given the heat output you need in BTUs or Watts, the formal measurements of heat outputs.

All convector radiators on our website show their heat outputs in BTUs and Watts

TOOL - Trade Radiators heating calculator.

What is the difference between single convector radiators and double?

The more panels and convector fins there are, the more heat the radiator will emit due to the increased surface area.

While a single panel just has one part to it, a double panel radiator will have two equal sections with a grill in the middle called convector fins. These help increase the surface area of a double panel radiator to help it heat a room faster.

You can get more information on the different features a single and double panel radiator have from our blog by clicking here.

What is a radiator pipe centre?

"A Pipe centre is simply the distance between the central points of the two pipe inlets on your radiator. Before making your radiator purchase, it’s always a good idea to measure the distance between your hot water pipes where you wish your new convector radiator to be installed.

You can then select a new radiator that has a Pipe centre measurement similar to the distance between your pipes. On all of our convector radiators suitable for a conventional hot water central heating system, you will see a ‘Pipe Centres’ measurement."

What type of radiator valves do I need?

All of our valves on are website are compatible with all of our radiators, however there are some variations to be aware of before you make your selection.

We offer three types of valve – straight, angled and corner valves and which one you need depends on the position of your existing pipework in relation to the radiator.

To view exactly what me mean more clearly, please view our helpful illustration

We also offer the choice of non-thermostatic valves, which keep the radiator operating at a constant temperature, or thermostatic valves, which allows you to vary the temperature of the radiator they are installed on.

If you are purchasing an electric convector radiator, you do not need radiator valves.

I need to replace every single radiator in my house but I don’t know where to start. Can you help?
Yes, we are very experienced with large projects that require complete radiator replacement. We can do a customized report that tell you exactly what dimensions and heat outputs you need in each room and can even give advice on style and finish. Please contact us on 0141 225 0430 or and we’ll be happy to discuss this further with you.

Installing and maintaining

Do your convector radiators come with wall fixings?

This is something that you should decide on before making your purchase. If you are happy with the position of your existing radiator, then it may simply be a case of using our heat calculator to establish what heat output you need and selecting a radiator accordingly, and with similar pipe centre measurements to your existing pipework.

It used to be popular to install radiators under windows, however with modern double glazing and insulation this is now not always necessary, so you may wish to install your radiator elsewhere. In this case it is likely you will need to have changes made to your existing pipework, so please consult a plumber to discuss it first.

Can I install my convector radiator myself?

Yes it is possible to install your radiator yourself, though we would only recommend this is you have considerable plumbing and DIY experience.

It’s preferable to hire a professional to install your radiator for you as this will ensure the job is done correctly and will possibly identify other issues you may not have been aware of.

Can I bleed my convector radiator myself?

Yes, this is one of the easier tasks related to radiator maintenance. All of our convector radiators have a removable bleed plug to make this job easy.

You can view Jimmy the Trade Radiators plumber bleeding a radiator below:

VIDEO - How to bleed a radiator

What if my convector radiator won’t get hot?

Any professional plumber or heating engineer should not leave your radiator without first checking that it is properly connected to your system and is getting hot. If this has happened then you should contact them immediately to come and check on the radiator.

If you have installed it yourself, then it’s a fairy easy fix and you can watch Jimmy the Trade Radiators plumber solving this problem below:

VIDEO - How to fix a radiator that won’t get hot

Should I add chemical inhibitor to my convector radiator?

Yes you definitely should and inhibitor should be added to your whole central heating system.

With hot water constantly running through your central heating system, there can be a chemical reaction between the water and the metal of your pipework or radiators which can quickly cause erosion inside your system. This can result in small pieces of metal breaking off into your system, causing radiator sludge, placing strain on your system and stopping your radiators heating up properly.

Simply adding chemical inhibitor can dramatically reduce this process and keep your heating system running smoothly.

To see what happens when you don’t add inhibitor to your system, please see the video below

VIDEO - Why adding inhibitor is beneficial to your heating system

What should I use to clean my convector radiator?

All of our convector radiators are very easy to clean, with large flat or slightly grooved finishes that respond well to cleaning.

Hot radiators attract dust, so you can use a vacuum cleaner to remove excess dust front the panels, convector fins and grills.

When wiping down the radiators, please use a soft cloth and warm water with a small amount of washing up liquid. Do not use an abrasive brush or household detergent as this could damage the finish.

What are Low Surface Temperature radiators?

LST's or Low Surface Temperature radiators are usually specified for jobs where there is a risk of the client burning themselves.

For a full description please read the following article

BLOG - What are Low Surface Temperature radiators?

Related Videos & Articles

How to balance your heating system

"‘Balance’ means that you evenly distribute the flow from the boiler and the pump to all the radiators in the house.

Making sure your heating system is balanced is a common thing to ensure your system is working correctly. "

Video showing a convector radiator being fitted

In this video, Jimmy the Trade Radiators plumbing goes through the process of installing a convector radiator in a conservatory.

It’s a useful video to see how a convector radiator is actually fitted, including how to measure up and move pipework. Additionally Jimmy gives some handy tips on how best to install a radiator in a room that has not previously had a radiator in it.

VIDEO - How to Install a Radiator in a Conservatory

Video demonstrating how to move a radiator

Quite a common issue is having a radiator on a wall in a room, when it would really be better suited on a different wall – often due to furniture or window placement.

Jimmy the plumber goes through the complete process of planning and then carrying out the task of moving floorboards and radiator piping to enable him to install a lovely new convector radiator in a more practical position under a window.

If you are planning to do this yourself, then please pay particular attention to the planning that Jimmy does in regards to which floorboards to remove and drill through and how to run the pipework neatly along the joist and beneath the floor.

VIDEO - Moving A Radiator Across A Room

Video replacing a small radiator with a large one

In older house that haven't been updated for a very long time, you quite often find radiators that are too small for the room that they are installed in. This usually means that the room feels quite cold despite the radiator being on full blast.

In this video, Jimmy the Trade Radiators plumber removes a very small radiator and replacing it with a much larger horizontal one that sits centrally under the window, not only being the right size to comfortably heat the room, but also looking much more aesthetically pleasing too.

Jimmy goes through the whole process from unpacking the new radiator, taking up the floorboards, measuring up and finally hanging the convector radiator to great effect.

VIDEO - How to Replace a Small Radiator With a Large One by Trade Radiators


Convector Radiator Feedback

Trade Radiators has carefully selected a superior collection of high quality premier white convector radiators. Our range of premier white convector radiators suit any room, large or small, for conventional central heating systems and electric only. Please see below a sample of what our customers have said about our service & products.

Many thanks for your really swift delivery of two radiators in perfect condition. The service has been excellent,I was a bit hesitant buying on-line as we have already got the plumbers putting a new boiler in. We could have gone to BQ, reserve and collect which was £70 more expensive and petrol to Plymouth! apart from the time taken.
M. Pearson, Devon

Just wanted to say a big thank you for a great service and top product. We purchased 10 stelrad radiators from you online which arrived as scheduled and perfectly packaged without any damaged items. I will have no problem recomending to friends etc, keep up the good work. Regards
G. Berntsen , Andover

The radiators were successfully delivered today. Thank you very much for a very prompt service
J, Brookes, Newbury

Excellent service very quick no problem delivery great web site so easy to use will definitely deal with this company again can highly recommend, many thanks.
J, Ellis, Kent

Thank-you for the very efficient service i received from you - radiator & valves arrived very quickly, our plumber has fitted the unit & we are impressed with how good it looks on the bathroom wall.
The website was very comprehensive & easy to use .
G, Garrill, Lincs.

Hello Trade Radiators,
Just a quick note to praise the service and products that I have bought from you.
Ordering was very easy: your website is easy to navigate and your prices are competitive.
I arranged delivery on a particular date and this was managed well and delivery took place as requested. The radiators were easy to install and they look fantastic - and certainly work well!
Thank you,
C. Warren, Stratford upon Avon

Very happy, radiators arrived on-time and as described. They are now fitted and look amazing.
Thank you
A. Pijohn, Whitley Bay

I dealt with Emma, she was excellent and couldn't fault you. Would readily recommend.
L. Fotheringham, London

Excellent service, easy to use website, prompt confirmation with delivery
details. Very pleased with the service and will use again.
S. Roche, Surrey

Radiator arrived safe and sound, probably the best condition I've ever received a radiator, pristine! All I need to do is to get on with plumbing it in!! Many thanks
C. Richards, West Sussex

Delivery speed - superb
Radiator - exactly as pictured
Very competitive priced
If I need any more I will come to you
D. Halmshaw, Mirfield