We are sometimes asked what Heatrae Sadia Amptec relay controls are for, and when they would be required. The answer to this is pretty straightforward, so we’ll, errr, relay it to you now.

Heatrae offer 3 different relays as optional accessories exclusively for use with their Amptec range of boilers. The RL1, RL2 and RL3.

They are all designed to enable high electrical load demands to be shared with the boilers. By this, we mean that if the overall kW capability of a dwelling is, for example, 14kW (approx. 61A) then it’s possible that a combination of a high demand appliance and the boiler operating at the same time would exceed this,  overloading and tripping the entire fuse board/consumer unit. The relays prevent the 2 items being in operation at the same time.

So why are there 3 different versions of these Amptec relays? Here’s an explanation of the functions of each one:

RL1 (95970134)

This is the most popular relay in the range. It is required when other high kW appliances could potentially be in use at the same time as a single Amptec boiler, which could overload the overall power capacity. For example, if an electric shower was in use, the relay would temporarily shut down the boiler. This is done in a controlled manner, so only the high current part is shut down, keeping the control side of the boiler active.

After showering, the boiler will re-start. Electric showers are typically only used for a short period of time, and so shutting the heating down for several minutes wouldn’t usually have any dramatic effect on room temperatures.

RL2 (95970135)

This relay is required when 2 Amptec boilers of high kW are in use in the same dwelling or on the same circuit - maybe one for each floor. It prevents both boilers operating at the same time which could overload the overall power capacity. Temperatures would still be effectively maintained as both boilers alternate to keep the water in the pipe/heating circuits hot.

RL3 (95970135)

As the RL2, but for 3 units rather than 2.

Not the most fascinating of articles you’ll ever read, but certainly factual.

If you’d like to spend more time on this riveting subject or if perhaps you would like to treat yourself to one of these relays then please feel free to ring one of our water heating geeks at Electrical Deals Direct on 01934 253600, or drop us a line: sales@electricaldealsdirect.co.uk