Safety Thermostat 7 inch to 18 inch

A safety thermostat is the cut-out that switches an immersion heater off when the water gets too hot. If the normal thermostat sticks on, this is the part that stops the cylinder boiling.

What a safety thermostat does

An immersion heater is an electric element that sits inside a hot water cylinder. It heats the water around it, and a thermostat turns it off at the set temperature. The safety thermostat senses the heat build up and breaks the supply once the limit is reached. So if a cylinder is spitting at the taps or the overflow is running hot, this part and the main thermostat are the first things to check.

• Options listed: 7 inch, 18 inch, 1/2 inch and 22mm
• Cuts the immersion off at its set limit
• For hot water cylinders with an electric immersion
• Works as a backup to the normal thermostat

Match the length and type to the old one, because a stat that is too short or too long will not read the water properly. Turn the power off at the isolator before you take the cap off the immersion. Then check the wiring diagram on the old stat. Electrical work should be done by someone competent to do it.

Immersion spares in Glasgow

Elements and spares are in our immersion heaters section.

Plumb Parts has its counter at 555 South Street, Glasgow G14 0QX, open Mon-Fri 8am-5pm and Sat-Sun 8am-1pm. Ordering online works as well.

Specification

• Sizes: 7″, 18″, 1/2″ and 22mm as listed
• Suitable for: Electric immersion heaters in hot water cylinders

Common Questions

What does an immersion safety thermostat do?

It is a cut-out that breaks the power to the element if the water gets too hot. It backs up the normal thermostat, which might stick on.

Which length do I need?

Match the rod length to the old stat and the immersion, so it reads the water at the right depth. Bring the old one into the shop if you are unsure.

Can I change it myself?

Only if you are competent with electrics. Isolate the immersion at the switch first, or get an electrician to do it.