WB Greenstar Highflow 440 - stuck on 't'.

Jeepers · Post by **Jeepers** » Mon Nov 11, 2024 4:02 pm

Hi all.
As the heading - this boiler has displayed 't' for days, and doesn't respond to a CH demand.
I understand the 't' means that the wee DHW storage cylinder inside is being pre-heated, but it should therefore only be on for a short while, and presumably go on and off then as required.
The issue came to light when the Hive controller stopped responding, and I found the batteries completely flat. Replaced them, and all is well - Hive-wise. It 'clicks' to demand CH, but the boiler does nothing. I bridged the two controller wires to by-pass the Hive, and now't.
The boiler has a built-in timer, but both DHW and CH are set to permanently 'on'.
I tried pressing 'reset' but now't. I tried turning the boiler off and on, and it displays P and a couple of changing numbers on reboot, and the red 'flame' light comes on for a half-minute or so, but then it settles to 't', and becomes unresponsive.
Am I missing something obvious, before I suggest they get a plumber out?
Thanks.

Someone-Else · Post by **Someone-Else** » Mon Nov 11, 2024 5:27 pm

First, I am NOT a heating engineer or Plumber. I would suggest you google to find out more about your actual problem, assuming you don't want to or other, you need a heating engineer, NOT a plumber. (Would you call a plumber to fix your washing machine? well it uses water, so a plumber can fix it) When you do call your company of choice, ask do they understand WB boilers. Or you could even call WB direct and get a "fixed price repair"

Good luck.

Jeepers · Post by **Jeepers** » Mon Nov 11, 2024 11:22 pm

Thanks S-E.

'Plumber' was just a generic term

I've messaged W-B to see if they can suggest anything. I'm just trying to avoid having overlooked something obvious - user-error - before I recommend they get their GS fellow out for a look. But drawn a blank, unfortunately.

Cheers.

Jeepers · Post by **Jeepers** » Tue Nov 12, 2024 8:04 pm

Occurred to me to check the really obvious - the system pressure. Hey-ho - it's at zero.

Connected up the filling loop, and sent some water coursing through - the needle didn't budge.

So there's clearly a bigger issue, and they'll be getting their regular GS out for a look.

Jeepers · Post by **Jeepers** » Mon Dec 09, 2024 10:36 am

GS came out, and stated to repressurise the system - it took some doing - as I went around all the rooms checking for leaks. Found one - a plastic tail supplying a rad valve.

Fixed by plumber, refilled, turned it on - thump thump bang bang. Diagnosed a U/S pump, and suggested we get a fixed-price repair from WB, as he was off on his hols! Someone else at the Unit knew of another plumber, but they are also too busy at this time of year.

I suspect the age of the boiler has summat to do with it!