Nothing is ever straight forward.
You're supposed to be able to isolate the CH system from the boiler and just drain down the boiler to work on it but the quarter turn valves weren't playing ball, had my whole bodyweight leaning on a big flatblade screwdriver trying to get them to budge, the return shut off but the flow wasn't having it and got seized halfway so had to fart around with a hosepipe out the front door and drain some CH water from one of the rads, enough to work on the boiler which is thankfully the highest part of the system.
Fitted the new expansion vessel, prv, siphon assembly and also fitted a new dhw heat exchange because sometimes when running hot water full bore from the kitchen mixer tap the boiler would bang (kettling) given the age of the boiler it was most likely scale build up in the heat exchange from the mains water.
Took the boiler CH union valve off and put it in the vice and it appears it's the head that's stuck but was able to open/move the ball valve with a flatblade screwdriver from inside.
Although the expansion vessel was new I still checked the pressure and it was 12psi so topped the system back up via the filling loop and everything works okay.
There's 10 rads on the system and I set the pressure to just over 1 bar and ran the CH, pressure maxed out around 1.8bar.
👇Old parts inc the temporary repair syphon assembly that did the job while I waited for new parts to arrive.
#fixstr 🔧
