No hot water, but CH works!!!

[chris_hesketh31]

Hope someone out there can help. I have a woucster heatslave 9.24 combi boiler, in the house I have just moved into. Today, although the central heating works fine, when the central heating is not running, (thermostat switched off CH), when I try for hot water the boiler refuses to fire up. I can hear water running through the system, and when the hot water tap is on, a click is heard from the boiler, but no boiler fires up. The same happens when the system is switched to hot water only. When the central heating is running(thermostat allowing the system to run), the water heats up OK!!! I did notice however that the pressure was <0.5bar. I tried again later on, and it worked OK, and I noticed the pressure was now 1 bar. There does not appear to be any leaks anywhere, and no water drips from the boiler. The radiators all work perfectly except one, which only gets lukewarm, no matter how much I bleed it, even though the pipe going to it, gets schorching hot. Any suggestions as to what may be happening would be appreciated.

rgrds

Chris

 

[boxster]

your radiator problem could be sludge. Your boiler however can be many things... i cant seem to re-call that model number but on standard combi boilers like vokera 80sp and others, its always the micro switch or diapram. I have even found the arm to be stiff. But as for your boiler i cant re-call the model i have worked on heat slaves before make sure you check the h/w exchager for leaks. The pressure will rise when the heating is on. Most heatslaves are fed of a tank in my area but this doesn't seem to the case for you.

ALSO if your radiator has a thermostatic valve check to see if the pin is stuck. get some plyers and pull and push a few time..DONT DONT pull it out all the way or you will get wet.

if it is a thermo valve

your boiler clicks first, it sounds like the micro switch.

 

[chris_hesketh31]

Thanks. I have noticed that when the system is not operating, the pressure drops to almost zero. When the central heating is running the pressure gets upto 1 Bar. In the installation manual, I sorced from the internet, it says during initial commisioning, the pressure should be 1.5Bar. I have no idea on how to rectify this, do I need to top up the system even though it is sealed, does water evaporate in a sealed system??, I have no idea how to top up a central heating system. Regarding the hot water, it now appears to work, although sometimes it taked a while for the bolier to fire up, and I wonder if this is a pressure problem too. Should I seek the advice of a pro to come an look at the whole system for me, as I have also noticed, that although the radiators get very hot, the rooms tend not to heat up very much at times. This may be unrealted to the heating prob though. Any advice would be very helpful here.

Rgrds

Chris

 

[boxster]

take the pressure up to 1.5 bar when cold. find a metal flexy pipe and turn the valve till the pressure goes up. i would call a gas fitter for a SAFTEY CHECK as its cheaper and get him to check it, if it was my company it would only be £35.00 for that but we mostly are doing emergency work at the moment