Only 4 out of 8 radiators working

[madge82]

The pipe to the hot water was warm and yeah sometimes the hot water does run really hot

 

[Hugh Jaleak]

First suspicion then would be the 3 way valve. If its not shutting off to the HW port fully, then the CH system will be robbed of water. Turning off the Hot Rads may not achieve much as if the resistance for the flow to get through the CH circuit is greater than the HW cylinder then the water will take the easier path. Is there a valve on the pipe leaving the bottom of the cylinder, underneath where the connection from the 3 port valve enters?

 

[durhamplumber]

8mm

Might be blocked

 

[madge82]

First suspicion then would be the 3 way valve. If its not shutting off to the HW port fully, then the CH system will be robbed of water. Turning off the Hot Rads may not achieve much as if the resistance for the flow to get through the CH circuit is greater than the HW cylinder then the water will take the easier path. Is there a valve on the pipe leaving the bottom of the cylinder, underneath where the connection from the 3 port valve enters?

 

[madge82]

I did think it could be blocked but there’s water going to the rad just cold

 

[Hugh Jaleak]

I did think it could be blocked but there’s water going to the rad just cold

How have you deduced that? Quite possible the rads are getting a water supply from one end, but unless there is throughput then they wont heat up.

 

[madge82]

Just read a lot of bad things about slim plastic pipes being used and ease of blockage.