Is the pump gone or is it sludge?

[slicedbread]

After a bit of advice here please.

I've just fitted a towel rail in the bathroom.javascript:emoticon('')
Very Happy

Now when I switch the heating on I get roasting hot radiators upstairs on the first two radiators from the boiler. The next two along upstairs are warm going but cooler going out, the last upstairs radiator is stone cold as are the three radiators downstairs.javascript:emoticon('')
Crying or Very sad

Now a bit of background the downstairs and last radiator upstairs have always been a bit cool since I moved in two years ago, so I've drained the system down and put cleaner in twice and things where a little better for one radiator downstairs and the one upstairs.

The pump seems to be running and I've taken the little cover off the impeller and it does wizz around quite happily.

Oh and one more thing - it hours for the radiators upstairs to get water in when I refilled - the header tank was nice an full but I bled - got a bit of air, then stopped, then a bit if air a bit later and so on until it was ok eventually.

Anyway - what's the opinion out there could it be something with the pump and convection is heating the first radiators upstairs or is sludge my problemjavascript:emoticon('')
Question

 

[JohnD]

have you balanced the radiators?

 

[Softus]

Sludge is your problem, or, even more likely, rust deposits.javascript:emoticon('')

 

[slicedbread]

We're going to try closing all the radiators off to make sure the flow are fully activated then open up one radiator at a time to see if this will clear anything.

What's the difference between rust deposits and sludge?

Any other suggestions. If it's sludge/rust deposits whats the remedy. It's an open system.

By the way is there an easy way to tell if the impeller is still actually pumping? It's still turning in the pump.

 

[Agile]

The pump seems to be running and I've taken the little cover off the impeller and it does wizz around quite happily.

javascript:emoticon('')

Are you quite sure you have seen the impeller?

I think you have only seen the end of the rotor!

Sludge is rust. But rust is not always sludge.

Tony

 

[Softus]

We're going to try closing all the radiators off to make sure the flow are fully activated then open up one radiator at a time to see if this will clear anything.

It won't "clear" anything, but it might move stuff around. Who knows, it might even shift it all into the boiler heat exchanger.

What's the difference between rust deposits and sludge?

Corrosion in a wet central heating system, containing dissimilar metals such as iron and copper, tends to result in Magnetite, which is one type of iron oxide, and rust, which is a different type. Magnetite has a sludgy composition, but can crystalise and harden. Rust particles seem keen on congregating together and forming impenetrable lumps.

If it's sludge/rust deposits whats the remedy.

An aggressive chemical cleaner and a Magnaclean type of device.

By the way is there an easy way to tell if the impeller is still actually pumping?

Clean the system out and see if all the rads get hot and the boiler doesn't kettle. Frankly, if your system has been dirty for a while then I'd condemn the pump and replace it once all the crud you can get out has been got out.

 

[Softus]

Sludge is rust. But rust is not always sludge.

Gibberish is nonsense, but nonsense isn't always gibberish.javascript:emoticon('') Really quite shocked and amazed

 

[slicedbread]

Are you quite sure you have seen the impeller?

I guess that's what I was driving at how can I tell the the impeller is still working and not just the rota?

An aggressive chemical cleaner and a Magnaclean type of device.

So next dumb question what is a Magnaclean device?

 

[Softus]

http://www.google.co.uk/search?q=magnaclean .javascript:emoticon('') Surely you could have done that

 

[Agile]

Are you quite sure you have seen the impeller?

I guess that's what I was driving at how can I tell the the impeller is still working and not just the rota?

You have to take the pump head off and inspect the impeller to see its not blocked with dirt or even fallen off completely!

An aggressive chemical cleaner and a Magnaclean type of device.

Softus said that not me!

 

[slicedbread]

Are you quite sure you have seen the impeller?

You have to take the pump head off and inspect the impeller to see its not blocked with dirt or even fallen off completely!

Sorry to be thick here but which bit is the pump head? You'll have to excuse me

 

[gas4you]

If it was taking for ever to fill up, I would also think you have a partial blockage in the cold feed to your system from the header tank, where it joins the heating pipe work.

For how cheap they are I would just fit a new pump

 

[slicedbread]

Ah well a text messge from home tells me that the pump just "made a funny noise and stopped going around" So I guess a lunchtime trip to buy a new pump is on.

Now I just need to get a replacment for a Grundfos UPS 15-50 from somwhere in Guildford

 

[gas4you]

Any local plumbers merchant will hold them in stock on the shelf.

 

[slicedbread]

Will it have to be another Grundfos or will other pumps fit the gap?