Fitting A Heated Towel Rail

Installing a new heated towel rails can seem daunting, but with a little common sense and technical know-how, it can often be done without the need to consult a plumber!


Selecting the right heated towel rail

To ensure you choose the a heated towel rails whose dimensions (or at least the relative positions of the water pipes) match as closely as possible with your existing pipework, as this reduces the likelihood of additional plumbing work being needed, and the ensuing re-tiling.

A lot of manufacturers (such as Aquaheat and Heatwise) have “standard” sized towel rails, whose piping arrangements are roughly analogous. So, the best way is to select a towel rail whose dimensions match your current one as closely as possible.

Another factor to consider is the heat output. The last thing anyone wants is a heated towel rails which either lacks the output to keep your bathroom warm, or is so hot that your bathroom may feel unpleasantly tropical! The output of heated towel railss is measured in BTU’s, or British Thermal Units. Many DIY websites include a BTU calculator, and the only technical information you’ll need are the dimensions of the room.


Replacing your heated towel rail

The first thing you need to do is drain your central heating system completely to prevent serious leaks.

Unscrew the pipes attached to the towel rail, bearing in mind that you should have a bucket nearby in case the central heating system still has residual water left.

Once your old rail is removed, remove any dirt and debris from the pipe ends, as this will be forced through your new towel rail and will damage it. Install your new heated towel rails as per the specific instructions included in the box, being sure to use the recommended number of screws (heated towel railss can be heavy, especially when full of water).

When connecting the pipes together, be sure to check that they’re fully tightened. Applying PTFE tape (plumbers tape) to the screw-threads first will give a watertight seal – PTFE tape is commonly available from DIY shops or most supermarkets.

Once the towel rail has been installed & connected to the water supply, refill the central heating system with water, making sure you keep a careful eye on your new towel rail, as this is when any leaks will become apparent – it may be safer to have someone near the stopcock to disconnect the water if you detect a water leak!

Having fitted your heated towel rail and refilled the central heating system, you’ll need to bleed the towel rail like a radiator, as some air will have become trapped during installation.

How To Drain A Central Heating System

Periodically, homeowners may need to drain the plumbing system in their home. This can be for maintenance, such as fitting a new toilet, sink, bath or shower. It’s also needed if you’re installing, removing or replacing a shower, such as a heated towel rail or new bathroom radiator (or radiator valves). You might also be leaving your home vacant for a while (particularly over winter) and want to remove the risk of cracked pipes and leaks.

Essentially all plumbing systems work in the same fashion, so these steps will almost certainly work. However, if you’re not confident, always consult an experienced plumber.


Disconnect the water supply to your boiler


A typical domestic thermal expansion tank.

This is easy to forget, but completely defeats the objective of draining the system! Turn the water off at the stopcock – this is often beneath the kitchen sink (but the location will vary between houses depending on the exact design).

When draining the heating system to carry out any work on your radiators, remember to switch off the gas & electricity supplies to the boiler (consult the boiler instruction manuals).

To prevent the system from automatically refilling, you’ll need to secure the ballcock in the “expansion tank”. This will be in your loft space. Gently lift the ballcock and carefully jam a length of timber underneath the rod it is attached to. If you don’t have a piece of timber, fashion a hook using some string & a wire coat hanger. Hook the coat hanger over one of the roof joists.


Draining the radiators

Radiator systems are designed with a “draincock” or drain valve on one of the downstairs radiators, which is intended to allow the water out via the lowest point (so gravity does the draining). Securely attach a garden hose to this, and put the other end of the hose down a drain in your garden. Don’t allow the water to drain onto paving slabs or over flowers beds/vegetable patches, as the water will probably be filthy.

radiator drain valve

A typical radiator drain valve, with angled drain. This will be found on a ground floor radiator.

Using an adjustable wrench, loosen the draincock until you hear water begin to flow through the hose. Once this is done, use a radiator key to loosen the bleed valves on the upstairs radiators, as this will allow air into the system and help drain the system more quickly.


Refilling the system

Make sure the draincock and bleed valves on the radiators are securely closed. If you’ve replaced a radiator, or radiator valve, be sure to check the pipes are sealed.

Once done, release the ballcock in the tank upstairs, making sure someone is keeping an eye on any work you’ve done to ensure there aren’t any leaks. Be ready to secure the ballcock & quickly drain the system if a leak is detected.

Some water pipes may creak or groan as the air is forced out, so don’t be alarmed!


Testing the system

Once the system is refilled, switch the gas & electricity supplies to the boiler back on. Switch the boiler on to allow it to heat up the radiators and drive any airlocks to the top of the radiators, from where you can bleed the radiators.