Worcester Bosch Heatlslave 12/14 pump steaming

[jmh1]

Hi
First time on here and what a wealth of top tips and experience. Please be gentle..

I have a Worcester Bosch Heatslave 12/14 combi. Got back home after a couple of days away and found house to be cold and boiler to be broken. Managed to get the chs working again for a couple of minutes when I pressed the thermostat reset button. Then it didn't work again all night despite a bit of fiddling. No DHW either. I vented the radiators about a week ago and there was a lot of air in them. I re-filled the system, but the pressure gauge is broken on the front of the boiler so had to guess when it had had enough. Radiators much, much better since. Boiler was serviced about a year ago by a local OFTEC engineer who said it was working fine and in good condition apart from the pressure gauge.

Anyway, managed to get CHS working again today - for about 15 mins then lots of steam started venting out of the pump. I obviously turned it off straight away. I am guessing the pump is broken? Is it worth checking the pump is working by following your FAQ 19 (http://www.diynot.com/wiki/plumbing:faq:faq19) or should I just call in an engineer now.

All help gratefully received.
jmh

 

[jmh1]

Just tried turning it on again and the fuse has now blown. Not having a good day! Anybody recommend where to get a T3.15AL 250v fuse. Can you buy them in B&Q etc?

 

[oilman]

The fuse is a 20 x 5mm 3.15 amp quick blow fuse. Maplin may be a possibility. I use a slow blow or anti-transient fuse, they don't blow as often. Take the screw out of the end of the pump and see if the shaft turns when the boiler is running. Have you vented the boiler? Needs doing just as rads do.

Why didn't "engineer" replace thge gauge? If it wasn't working when he "serviced" it, he couldn't service it.

 

[jmh1]

Hi Oilman and thanks for your reply.

I didn't vent the boiler itself when I did the radiators, I must admit I didn't consider it.

Not sure why the engineer didn't replace the gauge when he serviced the boiler, I guess as it all seemed to be working fine it was a bit of a cost shortcut for myself.

Thanks for your advice about Maplin, they have some fuses in stock so I'll pick some up tomorrow and then try the pump as you describe.

Another cold night....

 

[oilman]

.. I guess as it all seemed to be working fine it was a bit of a cost shortcut for myself.

If the gauge wasn't working, then he wouldn't have known if "it was all working fine".

Did he check the expansion vessel air pressure, (having released the water pressure by operating the PRV), and then reset the water pressure once the air pressure was correct?

 

[outinthestix]

The "T" part of the fuse number means "time delay" so it is a slow blow type fuse.