Potterton / Landis & Gyr system- CH when just HW & m

[Huddslass]

I have a Potterton Prima 50B gravity system which is 11 years old and controlled by a Landis & Gyr Programmer, Room Thermostat, Pump, Two-Port Valve and HW thermostat.

Recently had TRVs fitted on all our radiators (except one in the bathroom as required) and then a few months later had one radiator removed from the system and another moved to an adjacent wall.

A few things have happened and I'd like to know what I am talking about before I call my CORGI man...

1. The pump was making really loud whooshing noises then stopping then whooshing again (even after lots of bleeding) which I think we fixed thanks to you guys by lowering the pump speed from 3 to 2. Cured (I hope )

2. I have the CH off at the moment but it still comes on when the HW timer kicks in. I've got the room thermostat at zero as well which I would have thought would stop it coming on. I've looked at the valve above the pump and it is set to the Open position (rather than Manual)- is this something to do with it?

3. I read something about a flue problem in some Pottertons. Our boiler drips water when it rains (it comes straight in through the wall flue) and cuts off the electricity to the house! We have to switch the electricity supply to the boiler off when it rains. What will we need to do to get this sorted?

4. Finally, not all the time but sometimes the overflow to the loft tank drips when the HW / CH is on. I've had the ball cock mechanism replaced completely as that had gone (and it used to drip all the time) but it still dripping intermittently.

Sorry for bombarding you but you never know- they might all be connected! Any ideas????

Thanks
HuddsLass

 

[gas4you]

Radiator without trv should be in room that has room thermostat, so can't be bathroom due to electric regs.

Pump making whooshing noises sounds like lack of water in the system, possibly due to blockage in cold fill pipe. Turning pump speed down probably helped but not cured problem.

Heating coming on when it shouldn't sounds like 2 port valve fault. If its a Landisn&Gyr it will need replacing completely.

Overflow could be dripping to level in F & e tank rising when system is hot then cant refill system as it cools down to to possible blockage in cold feed, then causing pump to whoosh. Could also be pumping over and can't refill as well.

 

[Huddslass]

Thanks Dave. Our room thermostat is in the hall. Does that mean that the hall would have to be really warm all the time if we want the radiators to come on in other rooms which are much colder? We put non-TRV in the bathroom because it's ok for that to be warmer.

Any Potty guys out there know anything about the flue problem...it's pouring in today and fused the house once already?