screeching boiler

[lisa31]

Hi,

I have just replaced the diaphragm in my alpha cb28 boiler as i had no hot water.
The hot water is now working fine but when ever i turn the hot tap off the boiler screeches and whistles, the only way to stop this is to turn the boiler of at the electric and back on again.

Boiler pressure is fine and the diaphragm was fitted by my uncle who is a engineer.....any ideas what this might be as it says nothing in the manual about screechy whictly noises.

Any help would be appreciated...Thanks.

 

[jackecole]

can you listen and hear where the screech is comign from? could be air trapped possibly when the diaphragm was replaced

 

[lisa31]

Hi,

It seems to be coming from the new part......forgot to mention it only does it when the heating is on as well......just ran a bath and the heating is off and the where no noises.....

Thanks.

 

[jackecole]

sounds like it could be coming from the diverter valve - when it moves inside and changing ports

 

[lisa31]

is the diverter valve another name for the diaphragm ?? im a bit clueless ha ha......if it isnt is it something that will need replacing/repairing straight away....and is it going to cost me a small fortune ?

Thanks

 

[jackecole]

the diaphragm is a part in the diverter valve that allows hot water to fire the boiler up eg when a hot tap is opened. i'm not saying it is this for sure. can you open the hot tap etc and when the noise begins single out where it's comign from?

 

[lisa31]

i can open the hot tap and get constant hot water but when i close the hot tap thats when the screeching starts and the only way to stop it is to turn the boiler off.....the noise is coming from the area of the new diaphragm. All the radiators are hot.
Do you think it may be a case of trapped air as you said and will rectify itself after a while ?

I was thinking the bolier was protesting to the new diaphragm as the old one was destroyed ha ha.

Thank you for you advice by the way

 

[jackecole]

could be air trapped - might need slackening to remove but get ypour uncle back to take a look

 

[lisa31]

Thanks for your help.....i feel a bit calmer now ha ha

He said he will come back in a week to give it the once over anyway

 

[compheat]

I've never nown for air to be trapped on a diaphragm swap
never heard this one before

 

[Agile]

Call your uncle back!

 

[jackecole]

I've never nown for air to be trapped on a diaphragm swap
never heard this one before

yeah it can happen, as Agile says though, call your uncle back!

 

[mysteryman]

More likely the pump. Did Uncle top up the pressure afterwards?

 

[lisa31]

Had to call uncle back anyway......water decided it preferred to be on my floor than in the boiler !!

A pipe that we didnt have to unscrew ( the only one ) to get access to the diaphragm had worked its way loose and needed a new o ring......and to answer previous questions....yes the pressure was topped up straight away and the screeching stopped after a few hours, was just a bit unsure about it.....this boiler is starting to give me nightmares though.....

Thanks for all the advice though everyone......appreciate it