Downstairs radiators not heating up properly!

[wrecked_24_7]

I have been round to a customers house and they have an indirect hot water system, the hot water gets hot, and they say when the heating is on the upstairs get hot but downstairs do not. They had a new pump installed about 1-2 years ago, I think it might be the mid position valve, if not maybe the system needs flushing! ANy help or advice on this subject would be great, as I do find central heating a ball ache. Thanks

 

[leakylea]

replace pump

 

[Rydell]

I find that with a heating system, hot water produced from the boiler will normally, like hot air, rise up to the top rads first then with the help from the cirulator pump push the cooling water back downstairs to the rads then on to the return back to the boiler! If the rads are not getting as hot as upstairs then you should look to replace the pump, as mentioned above or look towards having a power flush with Kamco acid to remove any blockage or debri in pipe work. That is if you have checked all the rad valves to make sure they are in good working order.

 

[wrecked_24_7]

tyanku very much

 

[plumbnuts]

I agree it's most likely the pump. The short life of the last pump maybe down to crap in the system. Replacing it will probably cure your problem, but only for a while if the system is sludged.

 

[TerryH]

So, would the best all round deal be to flush the system thoroughly and then replace the pump? Is it possible to turn up the running speed of the pump and see if that helps? Even if it pushes some heat downstairs it is confirmation that the pump needs replacing. Possibly
TH

 

[leakylea]

put a screw driver blade on the pump body whilst it should be working and put your ear to the handle of the screwdriver, if you hear sound lke water running your pump is working
if you hear a constant buzzing sound pump is siezed, if its dead silent then no power is getting to the pump or the windings in pump have collapsed leaving pump useless. have you checked for power at pump? this could be a faulty component like a zone valve not fully opening and energising the pump etc
i would be surprised if heating working upstairs and not down is not the pump

 

[Bernie2]

Have you got a multimeter with Ohms on? Test pump for resistance? If its open circuit its probably dud. If you haven't got a multimeter. Turn off pump, undo cap nut and give impeller a spin. Replace cap nut and try pump. Don't forget most pumps have induction motors and will hum without turning the impeller, unless of course its burnt itself out. Try feeling the hot flow coming from the boiler to the pump, if its hot and the delivery side of the pump outlet is hot well past the pump, the chances are the pump is working but the system may be full of sludge.

If you do find its full of sludge, drain and refill it at least two or three times, do two hot flushes and a cold, adding Fernox or similar to keep the system clean.

Its unusual actually you usually find out a system is sludged up in the Autumn when you first start it up after a long period of lay off during the Summer, that is why its probably favourite to think in terms of a failed pump.

But why not do it all anyway?

 

[wrecked_24_7]

have you got a multimeter with ohms on? Test pump for resistance? If its open circuit its probably dud. If you haven't got a multimeter. Turn off pump, undo cap nut and give impeller a spin. Replace cap nut and try pump. Don't forget most pumps have induction motors and will hum without turning the impeller, unless of course its burnt itself out. Try feeling the hot flow coming from the boiler to the pump, if its hot and the delivery side of the pump outlet is hot well past the pump, the chances are the pump is working but the system may be full of sludge.

If you do find its full of sludge, drain and refill it at least two or three times, do two hot flushes and a cold, adding fernox or similar to keep the system clean.

Its unusual actually you usually find out a system is sludged up in the autumn when you first start it up after a long period of lay off during the summer, that is why its probably favourite to think in terms of a failed pump.

But why not do it all anyway?

very helpful, thankyou bernie!!

 

[Deleted member 2053]

Have you got a multimeter with Ohms on? Test pump for resistance? If its open circuit its probably dud.

Whilst this statement is true the reverse is not as you will get the correct reading across the windings if the capacitor has failed. But it still won't go.

 

[jas]

i also have the problem of no heat downstairs. boiler is quite loud and always give a loud bang when it fires up kettling?
pump is also loud can hear water being pushed all the time sounds like its struggling, could it be the pump then