Brass Immersion Heater Plug & Washer 2 1/4 inch

This Brass Immersion Heater Plug comes with a washer and screws into a 2 1/4″ immersion boss to close it off. Plumbers and householders use it when an immersion element comes out of a hot water cylinder and is not going back in.

Where it goes

Most UK cylinders take immersion heaters on a 2 1/4″ BSP boss on the top or the side. The plug goes in that boss when a failed element is taken out and the boiler now does all the heating, on a spare second boss, or on a cylinder where only one element is fitted.

Sizes available

• 2 1/4″ BSP male thread to suit a standard immersion boss

Fitting tips

Isolate the electrics and have the immersion wiring made safe and removed before anything else. Drain the cylinder down below the boss, then remove the old element with a proper immersion spanner, not grips. Clean the face of the boss, fit the new washer on the plug, and tighten firmly by hand with the spanner. Refill and check for weeps once hot.

Brass fittings from our Glasgow counter

For more plugs, sockets and adaptors, see our brass fittings. Collect from Plumb Parts, 555 South Street, Glasgow G14 0QX, or order online. Open Mon-Fri 8am-5pm, Sat-Sun 8am-1pm.

Specification

• Material: Brass plug with washer
• Connection: 2 1/4″ BSP male thread
• Sizes: 2 1/4″
• Suitable for: Blanking an immersion heater boss on a hot water cylinder

Common Questions

Can I leave a dead immersion heater in the tank?

You can, but taking it out and fitting a plug means nobody can switch on a faulty element by mistake. Get the wiring disconnected and made safe first.

Do I need to drain the whole cylinder?

Only below the level of the boss you are working on. A side boss means draining more than a top entry boss, so plan for a hose and some time.

Can I reuse the old immersion washer?

Fit a new washer each time. An old one has been squashed and heated for years and will often weep once the cylinder warms up.