Hello again – second post, but another plumbing problem – this time about our central heating.
We have a Glow-worm Ultracom 30hxi boiler that feeds our central heating and hot water. It’s controlled by a Drayton Lifestyle controller. The pump is a Grundfos Type UPS 15-60 130 Part number 5952660.
This system was installed before we moved in 2 years ago, so I’ve no idea how old it is, but it’s been working fine until recently.
Firstly, it kept failing with a fault code F25 on the boiler display, which is apparently “Maximum temperature rise slope”. I’d also noted some of the radiators were hardly warm, whereas others were hot. Anyway, I remembered that someone had commented sometime before that the pump was running on setting 3 (maximum), which was over-working the pump, so he’d turned it down to the mid-way 2 setting. I tried putting it back up to 3 and this stopped the boiler faulting on F25 all the time, though there was a lot of ticking noises coming from the pump. Anyway, I’d left it running like that for the past 3-4 weeks – no fault codes – ticking noise appeared to stop after a while.
However, in the past couple of weeks, I’ve noticed that the pump is running all night – even when the heating and hot water is off. I got up once at 4am and noted the pump was hot, but all the radiators were cold and the controller said that both the heating and hot water wasn’t on.
To prove this, I set a temperature monitor on the pump for 48 hours and right enough, this showed that the pump temperature was about 45 degrees whilst the heating/hot water was on, but when the heating went off, the temperature of the pump very slowly rose up to about 55 degrees, by which time the heating kicked in again, i.e. 5am in the morning.
So why would the pump be running all night and getting hot when the boiler is off throughout the night and periods of the day?? It's keeping me awake at night worrying about it!
