Cold downstairs rads - sealed system

[dundops]

Hi gang
I have just put our Vaillant EcoMAX 828 2E C/H system back on, but now find that I have hot rads upstairs and stone cold rads downstairs.

I know that at least one of the downstairs rads was suffering from sludge build-up prior to this (cold spot in the middle of the base of the rad.

I don't know anything about sealed systems at all, so I wondered if the cause is more likely to be a need for a powerflush, or a knackered pump. Or is it something more expensive?

Please help save my marriage!

Many thanks

 

[bab]

if you have trvs try turning upstairs rads off to see if any change. if u have trvs have they been turned down all summer as the pins under the removable heads can stick shut,

 

[dundops]

Hi - thanks for your quick reply!

TRVs all round the house, with a roomstat in the entrance hall. I have already tried turning off all the upstairs rads to see what would happen - result was an even colder house, with still no action downstairs! The c/h was turned off at the main timer all summer, with the TRVs left open, so I would not suffer the pins sticking on the TRVs.

 

[bab]

oooooooooh. have you drain off valve s on the downstairs rads id be tryingto drag some water through the pipework after shuting the boiler down to see if it will run warm, one side at a time, u will need to add water via fillingloop as well.

 

[dundops]

mmmm - looks like your theory is one of blockage then? 11.30 in the night is not a good time to try this kind of thing! However, I certainly have drain-off points on at least three rads downstairs. Investigation is called for!

 

[bab]

At a more reasonable hour connect up the drain pipe & let it run (recomend a jubilee clip on as well) ballance filling loop to maitain about 1/2 to 1 bar constant. then close the trv & check whats coming out of hose . let run a minute. then open trv . when trv open close lockshield end & observe. then close filling loop before shutting drain off. repessur to 1 bar open locksheild & fie heating to see what happens. if pump can heat al upstairs rads even if its on the way out it should manage one downstairs with upstairs off,