Little hot water, boost wont work

Hi

Im looking for advice please on my Plusacoil a class

Im getting hot water for 3 mins at 3 am
The boost button was working, but has now stopped
The header tank was dry, now filled.
No fault codes showing
I am competent around plumbing and electrical heating system
Any advice welcome

Neil

Hi,

Right ref boost if the unit is hot then boost will not work.
If unit is cold.
Then put boost on.
Checked the normal?
Heaters top On peak bottom one Off peak?
Supply to unit?
Checked the fault codes on the ACB as per the book?

You can try connecting a temporary supply to the OFF peak via a good piece of flex and plug top. And a heavy duty extension lead.
Make sure the OFF peak supply is isolated just in case it switches on whilst working. (E7 or E 10)
When you have the temp off peak supply on and the unit supply BE CAREFUL !!!!!
Check the bottom heater for live & neutral.
Check the relays too
Check out a previous post I made ref this and the interface relay. Not that long ago.
Watch what you are doing!!!!
Mike