bang when hot water turned on

[phi1w]

i had an ideal isar installed just before xmas. just recently i noticed a bang when any hot water tap is turned on, but only if the ch is already on. it's quite loud and i never noticed it before. any ideas please?

 

[chrishutt]

Clearly something wrong, possibly dangerously so, but the boiler must be under guarantee so just call back the installer. By the way was the installer Corgi registered? Did he complete the benchmark certificate? Did he notify the installation?

 

[phi1w]

yes all above board, i have all the correct documentation, i'll get him to check it out asap thanks

 

[ollski]

Possibly the diverter valve springing shut on the heating. Is is a single thud?

 

[phi1w]

yes it's just the one bang. it's worse if i turn the hot water on, and then off again quickly.

 

[keego]

Check the main stop tap is open fully, I had one like this before christmas, the stop tap had only been opened 1 turn & when you used the hot water the tap banged when the hot water was in use.

 

[timbalcombe]

sounds like water hammer to me?

 

[hammermarks]

Hi,

I have ISAR HE30 and it also bangs when a DHW demand is made during CH run. I've investigated and found the CP diverter valve is being pulled shut by the flow of water thro' it. Crap design. I'm in negotiations with Ideal over this and other issues

 

[hammermarks]

Hi Again,

just a thought, did Ideal sort your boiler?