No HW unless CH is on

[garry]

this is a old system with back boiler downstairs and a direct cylinder in bathroo upstairs the only way the customer can get HW is by turning the bathroom rad (1st) off its been like that for years but i said i would try and find somthing out to sort it but i cant think off anything to resolve this issue

 

[justlead1]

Hi. Garry, first thing to check is that the client put plenty of fuel on the fire, some will put a candle in the hearth and expect hot water and 6 rads. The next thing is to turn the lock shield valve down to balance the circulation, if one is not fitted, check the performance by using the wheel head to balance and monitor results before any alterations to system. Good luck