Hi! Hope someone out there can help!
I have a very puzzling problem with the central heating and hot water.
The problem is simple, when the hot water is turned on, all the radiators turn on.
Now the history:
Originally (20 yrs) the system we had was a potterton boiler with a hot water cylinder, cold water tank and gravity fed system. Everything worked fine i.e hot water and central heating was independent. Recently about 6-8 month ago, the problem arised. We assumed that there maybe something wrong with the bolier or hot water cylinder, and we were also in the process of getting a loft conversion. The vendor recommended we get an unvented system (some have megaflow we got a santon premier plus 210 litres) since we would have no room for a tank etc. So we decided to go for it, a glowworm 30sxi and a santon hot water cylinder and all the rads with thermostatic valves. We also have 3.4 bar water pressure.
After they changed the bolier and cylinder we still had the same problem!
Everytime we turn the hot water on, the central heating goes on.
So we called the plumbers (that did the new system) and they diagnosed the problem and said that our original system or circuit was connected wrong and that they could rectify it by bridging or connecting an additional pipe to the primary flow - i dont know the exact details but i can find out and post.
Today, they came round and spent the whole day trying to fix it by doing exactly what they said would fix it, but unfortunately it did not work.
My question is if anyone else experienced the same issue, and if they had theirs fixed? Also, all the zone valves were checked to be working. The thermostat also works, i.e if the central heating is on, and we turn the thermostat down, the heating eventually turns off, but even if the thermostat is down to begin with, and we turn the hot water on, the rads start heating up!
Can anyone help or give some ideas?
Help would be much appreciated!
Thanks in advance!