Heating Pump Noise

[Clueless11123]

Hi All,

I'll try and be as informative as I can to hopefully gain some advice before calling someone in to fix this - in the hope its something I might be able to do myself...

I have a Gravity Fed system and a condensing boiler. There is the usual large cold water tank and a smaller boiler feeder tank in the loft.

The pipe leading from the bottom of the smaller boiler feeder tank leads to the open vented boiler tank cupboard.

The pipe itself leads into my WILO, Wilo-Smart 25/6 (pictured below). This is situated on a vertical pipe.

Recently, the radiator in the Main Bedroom required bleeding. I have bled the radiator (with the boiler off), air escaped. After turning the system back on, the pump now seems to slow down and then speed up continuously, making a 'whirring/whoosing sound'.

I have 3 speed settings on the fan. Previously (2 years ago), when the pump was fitted, it made this noise after a few months. I turned the speed setting down from 2 to 1 and the pump ran much more quietly.

The 'whirring' sound that is intermittent is basically sounds like the fan at it's top setting of '3', but then slowing back down to setting 1 every few seconds.

I've bled the pump and this hasn't solved the issue.

Interestingly enough, the noise stops if I loosen/remove the screw on the pump (as if bleeding it) whilst it is running. I know I shouldn't do this when running, but if it wasn't for the water dribbling out, the noise could say gone!

Thank you anyone for any help or suggestions - any questions please ask me and i'll provide more detail as needed! Thank you!

 

[ScottishGasMan]

Don't think there will be much of a fix. Those wilo smart pumps are pants, seen a fair few doing the speeding up and slowing down nonsense if the decide to spin at all.

Possibly a video recording of it doing what it's doing could help us confirm its not air getting trapped in the pump, but tbh it probably needs replacing

 

[Lower]

I had the same problem with the same pump.

Wilo said the controller was faulty and replaced the pump under warranty. The new pump failed in the same way approx 6 months later. Changing the pump speed seemed to fix the problem for a while but it kept coming back.

I then replaced the pump with a 'proper' wilo smart pump (a Wilo Yonos) as the regs had changed and that one has been faultless.

 

[ScottishGasMan]

Would stick to using grundfos pumps, don't get me wrong they've had issues but stand out by a mile compared to most others in terms of reliability