Water Pressure in Performa 28

[briand123]

A couple of days ago the temp of the DHW in my Perfroma 28 suddenly started to cool down (the radiators are fine) when turned on full. I also noticed that the water pressure on the hot side seems to have increased. Presmably ( I'm guessing) that the water is flowing through the boiler too quickly to heat correctly. Is this likely to be a problem with the boiler or an external water company problem.Any advice would be gratefully recieved.
Oh yes I replaced the diaphragm in the diverter valve on the advice of the the local plumbing centre but it didn't change anything.

 

[Dan Robinson]

Does reducing the flow help?

From a cold start does the CH flow pipe get warm when the water is running?

 

[briand123]

Hi, thanks for the reply. Tried reducing the flow and yes the water does run hotter. I've been looking in the instruction manual to see if there is a way to reduce the pressure through the system but I can't see anything

 

[Dan Robinson]

Easiest way is with a bucket, and rad bleed vent, a rag and some bravery.

Unless you want to risk a drain point and a hose pipe.

 

[briand123]

Thanks once again, I'm no plumber but how will bleeding the system help the pressure in the hot water system and increase the temperature.

And of course the most important thing is, How do I do it?

Many thanksfor the replies

 

[Dan Robinson]

Apologies, for some reason I thought you wanted to reduce the CH pressure (brain not connecting properly... multitasking several times over.

The only way to reduce the pressure properly is to fit a pressure reducing valve.

Your problem is not pressure - it is flow.

 

[briand123]

Thanks I'll make enquies tomorrow about the valve. One last question though. Is it likely that the pressure can alter in some way of its own accord? or, Is there an underlying problem which I should get an engineer to check out.

Until a few days ago the pressure seemed much lower.

Many thanks for the help.

 

[Dan Robinson]

Your water company are in charge of that. they may have brought a new main onstream and given you a better supply - which is giving you worse hot water - now there's an Irony.

Make the most of it - get rid of the Potterton and have a real boiler