How should a pump be fitted?

[WillsNana]

Tried turning the cylinder stat down to zero. Left heating on low all night and my husband (who is now waking at 6 when the heating/water come on) says there was no pumping over.

Could it be a sticky motorised valve?

 

[WillsNana]

A different engineer called today. He checked the hw motorised valve which he said was working ok. He is going to order a less powerful pump and when it's installed will put the electrics at the top of the pump.

As we can't bleed the pump-see pics, do you think the valve over the ch boiler and one on the cylinder will get rid of the air (the pics are here //www.diynot.com/network/WillsNana/albums/ ).

 

[WillsNana]

And it goes on,,, We've been nursing the heating, it's either heating on and water off or vice versa otherwise it pumps over. Both work perfectly well if only one is on.

Today a new and less powerful pump was fitted and set to number 2 level. The plumber checked the valves, both ok. Although the overflow pipe was warm, it seemed ok, then both pipes were cool, so later I set the thermostat to middle heat (micron 70FF). Then it started pumping over, so we are back to square one.

Any ideas would be gratefully received.

Couldn't be the Hostman controls could it?

 

[ScottCheg]

Its blocked, well, partially blocked. The circulater is pushing water away from the boiler isnt it? The arrow will tell you that. You have a blockage somewhere, usually where the c/f and o/v enters.

Ignore your controls! They have no bearing with this problem.

Scott.

 

[sloppytom]

make sure the vent to the tank rises a minimum of 18 inches above water level

 

[twgas]

I would agree with ScottCheg on the blockage theory, or it may be piped wrongly.
Can you post pics of the whole airing cupboard and the area where the pump is (from greater distances) so that an assessment of the installaion can be made rather then guessing what is connected to what, and how.

 

[WillsNana]

Its blocked, well, partially blocked. The circulater is pushing water away from the boiler isnt it? The arrow will tell you that. You have a blockage somewhere, usually where the c/f and o/v enters.

Ignore your controls! They have no bearing with this problem.

Scott.

Our reg plumber had a look and suggested that the valves at the pump may be blocked, which he changed. They were really black, but it's still pumping over. He thinks that we may need a powerflush and a new heat exchanger.

What are "the c/f and o/v enters please?

 

[matt1e]

the spindle on the pump should be above the horizontal axis . Looks like it is slightly . Difficult to see exactly

looks like the shaft is vertical (and wrong) to me
( if that photo is looking down onto the floor that is)

matt

 

[WillsNana]

Sorry, should have said the pump has been installed correctly while he changed the valves.

 

[WillsNana]

Scotcheg what do you mean by
"where the c/f and o/v enters" please?

Been having a think, it says in the Micron book that to service you check the heat exchanger, and as it was serviced in November wouldn't Homeserve have noticed this? They've always said the boiler was very clean.

Can you find blockages with a magnet? Where might be the places to look?

Can a powerflush unblock a blockage (someone said no on another thread).

 

[WillsNana]

The heating only came on this morning (thermostat on cylinder is turned to off at the moment) and seemed to be fine.

A Homeserve boiler engineer came this morning and reckons that the heat exchanger is working fine. He tested it with some electric thing and said there was hardly a drop in temperature from one end to the other so it's not that, he says.

He turned on the hot water and turned up the stat, which automatically bubbled over. Now when we put on the heating only that bubbles over. Supposedly a Homeserve systems engineer will ring us now.

Is it really dangerous to keep the heating running when it pumps over.

And I'd still like to know what o/v and c/f are please?

 

[thefloosyonthebeach]

sounds like he meant (Cold Feed) & (Open Vent)

 

[WillsNana]

What a dipstick I am!