a desperate parent with young baby has no heating, it is a vaillant vp5 ze15 pump on the combi boiler which does sound like its working and the pipes are hot both sides of it as the pilot lights the burner but it switches off very quickly.

the pressure in the heating system seems fine and i have bled all the rads, there was lots of air in the system and re-pressurised it.

Is it likely that the pump is not pushing the heated water into the system which is why it then switches off and then when it cools a bit then tries again.

Is there a test I can do on the pump to qualify if it is worth replacing. I am trying to help this friend as she has major depression and gets swamped with life issues and has little to no money so i want to do my best as she was in tears which is why she phoned me as a support from self help group for people recovering from bereavement of her father dying two months ago.

 

if your description is correct, then you dont need to test the pump, it is not working.
are you sure there is electricity to the pump?
if there is, it likely needs replacement.
what brand and model is it?

 

the pump is the vaillant vp5 ze15 and it does sound like it is working electrically. it sound like it is spinning.
when i replace it obviously i know that i need to drain the system completely and then disconnect all the fittings to remove it and put the same thing back. it wont need calibrating or anything will it. just repressurising and bleeding the system.
also how does one go about putting any additive in the system, i am not clear about that either

 

you don't put additives in hydronic systems.

i am not familiar with that pump,but many pumps have a flange arrangment that eases replacement, you dont need to unscrew or solder anything,just unbolt the flange.
Look closely at how the pump is connectd to your pipes.
or post a picture

 

They do things a bit differently over there...

 

thanks guys, i did find the pump online with a pic of it. it is definitely the same pump. it is going to break the bank as she broke her leg on the ice two weeks ago and her car has blown up so i will hunt around for the best deal. is it likely that that i can get a recon one from somewhere

Vaillant VP5-ZE15 Pump 161106 [161106] - £113.32 : UK Plumbing, Online Shop

 

Rex, you mentioned that you think your pump is spinning. If that's the case then it is doing it's job and nothing will be gained by getting another pump which you obviously cannot afford and will probably not be able to return. Isolate the pump or you can drain the water out again if you have to, you have four screws that hold the pump head onto the body. Shut off your electricy to the pump and remove the head. Restore the power and if the impellar spins then the pump is good. That's all the pump does is move water. If it does that then your problem is elsewhere. On your supply pipe going out of the boiler you may have a flocheck valve with a thumbscrew on top. It could be stuck. If you do have one you can open it up to maual position by turning the screw counter clockwise and the water will flow by gravity. Just make sure the system is free of all air when you're done. Also you mentioned there was a lot of air in the system. Once the system is bled and air free it should stay that way unless there is a problem or a leak somewhere that lets fresh water feed back in which brings air with it. You might want to look at that also. Good Luck.

 

Spot, that is really useful advice thank you. I have been over there for hours trying to identify the right pump and couldn't get one but now have definitely identified the correct boler and model. it is the vaillant compactcombi vcw 242e or 282e both of which take the 161106 vp5 ze15 pump.

I have been really worried about buying it and it not being the problem as it will take half my benefit as she is not in a position to at the moment. I want to do it right cos she is a lovely girl who needs a boost in life. i am only alive today because others showed me the same spirit so this is how i give something back to the world.

So thank you for helping me out guys it is a lot more meaningful than you probably realise.

 

i may be back with some more info once i have done the test

 

Thanks spot, the pump is spinning so thanks for saving money for us.
I am not sure what to do next. the water around the pump seems to get hot but it doesnt travel to the rads. Also the burner does fire up but the switches off very soon after,