Heating woes

[yakflyer]

Recently returned from holiday and we are getting a problem with our central heating.
Whilst away the heating was left running but on a reduced heat and no hot water setting.
The rad's upstairs get hot and a couple downsatirs get warm. If I turn all of the upstairs rad's off I can get each of the downstairs ones to warm up (one at a time)
Seems to me it might be the pump. I have reomved the front screw on the pump to see if there was a large flat head screw (as mentioned in other posts) to turn to check if it's jammed. No large screw in there.

The Boler is a Vaillant and the label says : VU 142/1 E, 182/1 E, 242/1 E, 282/1 E

The inside looks just like the phot in this post
//www.diynot.com/forums/viewtopic.php?t=102331

Is there a way to check the pump is spinning? or how do I remove and clean it.

Thanks

 

[bengasman]

Put your finger on the plastic part of the pump.
Pump should be on setting 3

 

[yakflyer]

I can feel some flow vibration when touching the plastic part of the pump

Any other ideas?

 

[bengasman]

Could be a number of things e.g. pump on the way out, blockage, poor balancing, faulty bypass; probably a combination.

 

[yakflyer]

Ok, Thanks.

Lived here a while now and the heating never gave any problems. The balance seemed good as all rad's were getting hot. Blockage is likely I guess.

Thanks for trying to help.

 

[yakflyer]

How do I remove the pump head so that I inspect and clean it?

I know about the four screws on the flange, just not sure where and how to isolate the pump.

Thanks