Baxi Boiler Pressure and Warranty Issue

Kalyke

I had a Baxi Combi installed recently. A couple of weeks after installation I bled a radiator, the pressure dropped and the boiler stopped working. I called (and called and called) the installer for help but he never replied. I found a valve in the hotpress that pressurized the system. I then had a local plumber have a look at my system. The "expansion" tank was disconnected. That is no input or output. He says he can sort it for me. If he does is my Baxi warranty voided? If so, what is my next step as the installer will not reply. (He is RGII registered) Can I complain to Baxi or RGI? Thanks.

Ger Roe

Get on to Baxi directly. Your installer should have registered the installation with them and then the guarantee starts.

Even if he didn't, talk to them yourself. I had similar issues with pressure problems at the start of my Baxi experience and found them very helpful and willing to fix issues.

The expansion vessel is a pain of an issue, any problem I have had with the boiler over the years, installers and servicers go immediately for the expansion vessel replacement response - it has never needed replacement.

Pete67

A couple of things. If the new boiler has an internal expansion vessel, then the external one may not be needed. However the installer should have explained this at the time. Pressure drop after venting radiators is normal and unavoidable on a sealed system. Your installer should have demonstrated how to maintain the boiler pressure when he was handing over the new boiler, but it seems you have found this now anyway.

Here's what I would do. With the heating off and system cold, top up the boiler until the gauge is at 1 bar, and then close the fill valve. It really should be disconnected when not actively in use for topping up. Then vent your radiators (all of them, it's common for a small amount of air to need venting a week or two after filling the system) checking the boiler pressure every now and then as you are going around to keep it at around 1 bar.

When you are confident that you have all the air out of the radiators, and the pressure is at 1 bar approx, fire up the heating and watch the pressure gauge. It should rise up a little when all the radiators get hot, but should not go to much more than approx 2 bar. If that's the case then all is well and you just need to check the pressure gauge every couple of months, it should remain at 1 bar with the heating off and radiators cold. You might need to top it up once or twice a year. Any more than than would indicate a leak and should be investigated.

If the pressure rises rapidly to over three bar when heating up then either there is no expansion vessel in the boiler, or it is not working correctly. This is a more serious problem and needs to be rectified immediately. While the safety valve SHOULD operate to release the overpressure this is not a safe condition to operate the heating system in.

Kalyke

Pete67 wrote: »

A couple of things. If the new boiler has an internal expansion vessel, then the external one may not be needed. However the installer should have explained this at the time. Pressure drop after venting radiators is normal and unavoidable on a sealed system. Your installer should have demonstrated how to maintain the boiler pressure when he was handing over the new boiler, but it seems you have found this now anyway.

Here's what I would do. With the heating off and system cold, top up the boiler until the gauge is at 1 bar, and then close the fill valve. It really should be disconnected when not actively in use for topping up. Then vent your radiators (all of them, it's common for a small amount of air to need venting a week or two after filling the system) checking the boiler pressure every now and then as you are going around to keep it at around 1 bar.

When you are confident that you have all the air out of the radiators, and the pressure is at 1 bar approx, fire up the heating and watch the pressure gauge. It should rise up a little when all the radiators get hot, but should not go to much more than approx 2 bar. If that's the case then all is well and you just need to check the pressure gauge every couple of months, it should remain at 1 bar with the heating off and radiators cold. You might need to top it up once or twice a year. Any more than than would indicate a leak and should be investigated.

If the pressure rises rapidly to over three bar when heating up then either there is no expansion vessel in the boiler, or it is not working correctly. This is a more serious problem and needs to be rectified immediately. While the safety valve SHOULD operate to release the overpressure this is not a safe condition to operate the heating system in.

Its a Baxi 624 system boiler lpg. The absence of communication from the installer is very worrying.

Refitting the tank will only mask a leak on your heating system which is no Benefit for you.

The first thing I would want to know is the heating system losing pressure(the above posts will help you determine this), if you are losing pressure then deal with the leak or the cause, if your not losing pressure then you have a perfectly good heating system.

Pete67

Baxi 624 has an internal expansion vessel. You don't need the old one, which is why it was disconnected and blanked off. The installer should have explained this.


https://www.baxi.co.uk/our-boilers/system-boilers/-/media/websites/baxiuk/files/product-literature/baxi-600-system/7686961-01_baxi_600_system_install1.pdf?la=en&hash=2ABFB741C8ADB640657D17468B5ECE21B215F687

John.G

The above boiler has a 7 litre EV pre pressurised to 1.0 bar. With the system cold and after all air has been released then it should get a filling pressure of 1.5 bar, this ensures that there is a reserve of 1.4 litres when cold and you can then judge the leakage rate (if any) as the EV will loose 1.4 litres of water falling from 1.5 to 1.0 bar. A 7 litre EV will result in a final (hot) pressure of 2.3 bar with a total system contents of 85 litres and/or 2.64 bar with total system contents of 100 litres sufficient for ~ 12/14 rads, if the pressure is higher than this from the above conditions then a second EV must be installed to avoid lifting the boiler safety valve (PRV) at it's maximum safe working pressure of 3.0 bar.