Noisy on producing hot water - Baxi Combi 133HE Plus

[LisaF1]

As previously advised we fitted a new expansion tank, as it was found to be faulty. The problem went away but now IS BACK!!!!

I've checked the new expansion vessel and it seems that that's now damaged too. There must be an underlying problem which is damaging the expansion tank. Any ideas??? Anyone???

A bit of history......

My boiler (a three year old Baxi Combi 133HE Plus) is making an awful noise when hot water is demanded. especially if the heating is off, but does make the whining/grinding noise even when the heating is on. I've found that filling the system slightly alleviates the noise, but it doesn't go entirely. The heating is working fine.

The system's pressure is also extremely variable from nothing when it's off (is this normal for a pressurised system?) to up in the red when the central heatin is on. One minute you can look at the dial and it might be low or normal, but this can change in a few minutes to being too high or too low - it's all over the place! I have noticed that water occasionally drips outside from a valve (pressure relief - I'm not sure?). I've tested it to see how much and it can leak up to an inch in depth of a small washing up bowl over a couple of days.

Our gas chap recently serviced the boiler and said that there's nothing wrong with it - but clearly there is!!

Can anyone help - yes, we've got hot water and central heating, but the water is noisy and I'm fed up of constantly having to do small fill-ups to restore the pressure.

I'd be very grateful if anyone could shed any light!!

 

[gas4you]

Your system pressure should be just over 1 Bar when syatem/boiler is cold.

Depending on the size of the system, one would expect the pressure to rise no more than to about 2 Bar when rads fully hot.

How many rads on your system? Could be the exp vessel fitted to the boiler is not big enough for your system size.

From what you state at present, either the new expansion vessel has lost its charge, or has holed again.

Follow the instructions again in the FAQ's and test the exp vessel again.

Oh and while you're at it, get an engineer who knows what he is doing

 

[shawd]

Check the pressure in the expansion tank should be 1 bar, you can only check it with the boiler drained down, fit new prv valve , clean the return filter to the heating and if that doesnt cure noise fit new or clean hw plate heat exchanger,,, only drain boiler by valves underneath never by the prv as some people do. That should sort it