Worcester Bosch 240 RSF - pump combatability?

[studarude]

Hi all,

I've been having a recurring problem with my WB 240 RSF, she's a little long in the tooth now i know but other than an intermittent pump problem has been great.

What happens is when the hot water tap is opened, the boiler starts, and very quickly a plumbers hammer type noise appears, the pressure in the heating system raises by half a bar then the temp cut out kicks in shutting the boiler down.

On closer inspection it seems that the pump is stalling; i've ran the hot tap with the vent plugged removed and a little tweak on the shaft will get the pump running again and it'll be fine for a few days before happening again etc.

Does this sound like a pump failing?

If so, the pump currently installed is the usual red WB/Grundfos 15/60; ive got access to a brand new orange Grundfos UPS 15/50 so other than the reduction in head height (6m vs 5m i believe?) will there be any other issues in fitting this pump?

I had intended on just fitting the head as an interim test measure, leaving the body and hence unions undisturbed...

Thoughts?

 

[Agile]

I think that most Worcester boilers of that age use a greenish grey coloured Grunfoss. So the current one may be a replacement.

Don't assume that all pumps by the same maker are the same! Some are slightly different and particularly Wilo pumps!

Sounds as if you may have dirt in the system blocking the pump. Possibly using a sludge remover might cure the problem?

Tony