Worcester Bosch Combo Power Cycle / Restart Question

[JamesK]

Hi All,

I've got a question about my Worcester-Bosch 34 CDi Classic combo boiler. If the boiler is power cycled it takes approximately 20 minutes before the central heating will work.

On the boiler temperature display it alternatives between the temperature and the -| |- symbol. I've attached a picture, and here's a link to a small video showing it: YouTube Video Link

Hot water isn't affected and is available immediately.

I recently asked the British Gas person who serviced the Boiler and he just said "It's fine, they all do it". That's obviously good, I was just interested to know what the boiler was doing, and why there was a delay on the central heating being available when the hot water was available immediately.

 

[harrythefurrysquid]

According to the manual:

The boiler runs for 15 minutes at minimum heating output to fill the condensate trap. The display alternates
between [+] and the central heating flow temperature. This occurs every time the mains supply has been interrupted.

 

[JamesK]

According to the manual:

The boiler runs for 15 minutes at minimum heating output to fill the condensate trap. The display alternates
between [+] and the central heating flow temperature. This occurs every time the mains supply has been interrupted.

Many thanks for this. The boiler was installed by the previous owner of the house, and didn't leave any instructions for it behind.

 

[muggles]

This annoying feature can be turned off, and frequently is by engineers who don't want to stand around for 15 minutes waiting for it to sort its life out after a service

 

[JamesK]

What I don't understand is that it only does this for central heating. If you open a hot tap the boiler immediately fires up.

 

[muggles]

That's how it's designed. Hot water demand overrides pretty much everything except lockout faults