Horstmann Economy 7 Quartz not heating water in timed mode

[neko1705]

Hello Everyone,

My boiler stops working in timed mode. The boiler is connected with Horstmann Economy 7 Quartz timer. It works perfectly in Boost mode (the boost indicator light will lit up while boiler is working). But it just stopped working in timed mode.

I have been quoted £160 plus VAT to change a new timer including labour. Before I call the engineer to change it, I am wondering if there is anything I can check it myself.

Attached photos are the inside wirings. Could you kindly let me know which parts should I test and is it a simple job I can fix it myself or I better just leave it to the engineer? Thank you very much for answering the questions.

 

[OwainDIYer]

Are you sure it's the timer? You appear to have off-peak load and boost load connected - two immersion heaters?

I think it's more likely the off-peak immersion heater over-temp stat has tripped or the element is faulty.

This assumes the Horstman is set at the correct time and goes round and round correctly.

If you do decide to change it yourself, and replace like with like, the connections 12345 just pull off the base unit and the new ones just push firmly on.