I have a Combi System Worcester Heatslave oil boiler which contains a Bosch water pump. When I remove the large screw on the front of the pump water comes gushing out. Is this indicative of a problem with the pump?
When I have removed the similar screws on Grundfoss pumps water has not come rushing out and I have been able to use a small screw driver to make sure that the rotor can rotate.
it's normal with CH pups.
Usually it does come out.
NT
What is it then, just a thrust bearing? Seems a little crude. No wonder my neighbours pump sounds like its big ends gone all the time.... Brian
Thank you for your reply. If I remove the screw the shaft does not rotate by itself when power is applied. I can turn it quite easily with a screwdriver. There is an arrow on the cover which I assume indicates the direction of rotation (anti clockwise.)
Either power is not being applied or its f***ed.
It turns out that I can just buy a new head which may be easier to fit for £100.
Check that is is not a failed capacitor in the plastic box on the side also that the speed switch is not dodgy or between settings.
It doesn't necessarily mean that. Removal of the screw can cause stoppage, and return of the screw can make it run fine again.
NT
When I used a small screwdriver to turn the pump it did make a slight scrapping sound so I went and bought a new pump head, which turned to be made in Serbia by Grundfos a Dansih company. The new pump head did have a label with Bosch written on it. Fitting the new head was quite easy, much easier than trying to undo those big nuts on the isolator valves for Grundfos pumps. I am pleased to say that my radiators are now warm.
Next time just turn it several turns, you may find the scraping ceases & it runs well again.
NT
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