Radiator restoration and valve configuration

07 June 2024

At Radrestore we can refurbish reclaimed and reproduction cast iron radiators. Configure old radiators to accept modern valves, fix or replace original and newer reproduction cast iron radiator sections.

Radiator restoration and valve configuration.

You’ll first need to remove the old paint. The best way to do this is sand blasting. There are many companies that provide a sand blasting service, including Marple blasting services. Once all old paint is removed and your radiator is back to the bare cast iron, it is best to prime the radiator to prevent rust –  exposed cast iron rusts very quickly.

At this point it is time to think about connecting the radiator to a modern central heating system. It is unlikely that all valve connecting bushes and plugs will fit a modern day central heating system so you may need to replace them. All cast iron radiators will have two reducing bushes (valve bushes). These are the point of entry and exit for the hot water and are generally located at the bottom of the radiator. It is the valve bushes that are most likely to need replacing to fit a modern central heating system, as they are either too big for modern day central heating systems or configured on the radiator to suit older heating systems.

At the top of the radiator there will be one blanking plug and one bleed bush, to accept a bleed valve. These are not likely to need replacing unless they are damaged or configured in the wrong position. To remove, unscrew the bush or plug using an adjustable spanner. All reclaimed cast iron radiators that we have come across have right-hand threads for external bushes and plugs, so left to loosen. Due to the age the of reclaimed cast iron radiators they are usually pretty rusty so they require a good amount of pressure to unscrew. A short piece of scaffold pole to extend the length of the spanner handle and provide more torque on the bush, laying the cast iron radiator on the floor helps you to apply more torque too.

Most modern thermostatic or manual radiator valves have a 1/2″ BSPT (British Standard Pipe Tapered) connection to the radiator, which equates to a 21mm hole into where the valve tail is inserted. Radrestore can supply sets of bushes that will reduce the hole in the radiator down to the 1/2″ BSP size required to connect a valve.

A little about BSP sizes: British Standard Pipe fittings come in parallel or tapered thread. The fittings on original antique reclaimed cast iron radiators are usually BSPT (tapered). The seal is made at the contact between the male and female threads with their tapered shape meaning that the contact area between the threads increases with each turn. To ensure a strong seal is achieved, it is absolutely essential that a good sealant is used when screwing in the end bushes. This is because cast iron is often pitted. For this we recommend LSX Sealant.

Once all four ends are sealed and you’ve checked that the bleed valve is working (if not you can buy new bleed valves from Radrestore https://www.radrestore.co.uk/products/accessories ), you’re ready to connect the reclaimed radiator as any other new radiator, though you’ll probably want to paint it first. We have a wide choice of finishes here https://www.radrestore.co.uk/products/radiator-finishes.

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If you have any question or comments, or if you need a quote, please use the form to the right, or the contact details below, and we will get back to you as soon as possible.

Visit our showroom in Manchester, we can assist you with all your radiator requirements. Please call 0161 843 8163 or email [email protected] to book a day and time.

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