Horstmann BX2000 - hot water for 1 minute then cold

[LM23]

Looking for some advice please, I moved into new build flat around 4 years ago with this system fitted.

We’ve never had any issues with hot water however for the past week, we get 1 minute of hot and then it goes cold. To my knowledge we’ve not changed any of the settings (below). Any idea what could cause this?

Thanks in advance!

 

[CBW]

Could be a faulty/failed element or thermostat.

 

[LM23]

Could be a faulty/failed element or thermostat.

Thanks, we put the boost for an hour worked normally however concern only working with boost on.

Would that rule out faulty element or thermostat?

 

[CBW]

Thanks, we put the boost for an hour worked normally however concern only working with boost on.

Would that rule out faulty element or thermostat?

I would say if it’s working on boost, then yes. Maybe it’s a loose connection somewhere? When you have it via the timed period, does anything light up on the Horstmann?

 

[LM23]

I would say if it’s working on boost, then yes. Maybe it’s a loose connection somewhere? When you have it via the timed period, does anything light up on the Horstmann?

Yeah when we put the boost on, the red light comes on so doesn’t seem to be an issue with the horstmann. Had a check for loose connection and everything seems to be fine.

Put the 1 hr boost on at 11.30am yesterday had a shower later that evening at 6.30 and it was working perfectly however shower this morning ran cold after a minute again so back to square one!

 

[flameport]

FCU has failed and needs to be replaced.
Preferably with a 20A switch and not a 13A fused affair.

 

[LM23]

View attachment 299807

FCU has failed and needs to be replaced.
Preferably with a 20A switch and not a 13A fused affair.

Thanks, can you confirm what the FCU is please? I’m useless at this type of thing!

Would the peak not kick in if the off peak has failed however?

 

[flameport]

Fused Connection Unit
The item with the switch and the cracked fuseholder.
No reason for it to be there at all, but as it is, the easiest option is to replace it with one of these: https://www.screwfix.com/p/mk-logic-plus-20a-1-gang-dp-control-switch-white/44956 with no fuse.

Peak only works if you press one of the boost buttons.

 

[LM23]

Fused Connection Unit
The item with the switch and the cracked fuseholder.
No reason for it to be there at all, but as it is, the easiest option is to replace it with one of these: https://www.screwfix.com/p/mk-logic-plus-20a-1-gang-dp-control-switch-white/44956 with no fuse.

Peak only works if you press one of the boost buttons.

Thanks mate, had a look and it’s all burnt out. Will get it sorted tomorrow

 

[ianmcd]

@tonybhoy this post remind you of anything mate