Baxi bermuda 401. Boiler works fine, no heat to the radiators.

[garnet]

Hi all, I have a baxi bermuda 401 back boiler.
The boilers working fine, no issues with it itslef.
I started the heating, boiler heated the water, all radiators were hot. Except the one in the hallway where the thermostat control is. It was only hot at the bottom. So I figured there was ait in it. So I bled it, air came out.

Than I noticed the burner on the boiler was off. Which was strange as this was less than 10 min and the house was not at 24 degrees yet. So I increased the water temperature on the boiler. Burner started and 2-3 min later it was off. As if the pump is not moving water in the system or the valves are stuck shut. Or the water level is low. It is an S- plan system with 2 valves. I can see the pipe is hot past the pump to the lower valve (vertical), but not furter down (which should be flow).

Can the bleeding be the problem? There was a leak from one tap on pipe that is connected somehow to the system 9 months ago, it was fixed and the heating was working OK since then. All started after I bled this one radoator.
Help much apprecieted.

 

[martygturner]

check that the little metal flag on the motorised valves actually move when you call for heating ie turn up the thermostat...

 

[garnet]

check that the little metal flag on the motorised valves actually move when you call for heating ie turn up the thermostat...

Do you mean the little metal lever thing in the top of the valve? I dont think it moves, but I tink it never moved, even when it was working OK.

 

[Johntheo5]

With the heating off, pull on that lever, you should feel a fairly stiff resistance immediately when you start pulling it across, then fire up the boiler, ensure heating thermostat is calling for heat, there should now be no resistance when you "pull" the lever.

 

[garnet]

With the heating off, pull on that lever, you should feel a fairly stiff resistance immediately when you start pulling it across, then fire up the boiler, ensure heating thermostat is calling for heat, there should now be no resistance when you "pull" the lever.

If this is the case what does that nean?

 

[Johntheo5]

If the boiler fires up when you turn up the roomstat it should mean that the zone valve has moved across and its end switch has requested the boiler to fire up which I think it has but you can prove it as per above, if its a sealed system check the boiler pressure not less than ~ 0.7bar. If open vented check that the feed and expansion (small) cistern has water in it, also check that the circ pump is running.

 

[ChrisJP]

It seems likely that one or other of the motorised valves (the rectangular silver boxes in your picture) has failed - probably the microswitches that fire up the boiler when the valve is powered open have become unreliable.
New heads are available containing the motor, gearing and the microswitch and these can therefore be replaced without touching the valve itself

 

[garnet]

If the boiler fires up when you turn up the roomstat it should mean that the zone valve has moved across and its end switch has requested the boiler to fire up which I think it has but you can prove it as per above, if its a sealed system check the boiler pressure not less than ~ 0.7bar. If open vented check that the feed and expansion (small) cistern has water in it

Thats the thing. I think it might be either a stuck valve or/and lack of water in the system. It is open vented. Check for water, I can not do this myself as the vessel is in the loft. Thinking about it if I let almost a full radiator of air out, that might be that the water level dropped.
Can anyone recommend a gas repair guy in Edinburgh?

 

[Johntheo5]

Can you get a neighbour or relation to climb up and check?, the ball cock may just be stuck up, shut, if its given a tap, it should fall down to refill the cistern.

 

[DP]

It seems likely that one or other of the motorised valves (the rectangular silver boxes in your picture) has failed - probably the microswitches that fire up the boiler when the valve is powered open have become unreliable.
New heads are available containing the motor, gearing and the microswitch and these can therefore be replaced without touching the valve itself

If the valve actuator is gubbed then boiler would not activate when that zone is switched on

 

[garnet]

Thanks all,
It al points to the motorized valves and/or water in the cistern. Can this be sorted out by a plumber instead of a gas enigneer? Boiler is not to be tweaked with.

 

[numpty1]

your previous thread indicates issues with the boiler hence your reluctance to employ a competent person who could help and advise you.

 

[Johntheo5]

Thanks all,
It al points to the motorized valves and/or water in the cistern. Can this be sorted out by a plumber instead of a gas enigneer? Boiler is not to be tweaked with.

IF the boiler is firing up when you request CH or HW then its almost certainly NOT either a motorized valve problem or a boiler problem, lack of water definitely a prime culprit if the circ pump is running, or possibly air in the system, in which case a plumber should certainly sort you out if you can't get someone to rule in or out a water shortage by just looking into the F&E cistern. If the cistern is "full" then also the possibility of a blockage somewhere, plumber should sort it.

 

[martygturner]

IF the boiler is firing up when you request CH or HW then its almost certainly NOT either a motorized valve problem or a boiler problem, lack of water definitely a prime culprit if the circ pump is running, or possibly air in the system, in which case a plumber should certainly sort you out if you can't get someone to rule in or out a water shortage by just looking into the F&E cistern. If the cistern is "full" then also the possibility of a blockage somewhere, plumber should sort it.

err what his boiler fires up goes for 2 minutes then shuts down and he bled the rad how would he bleed the rad without water ?.. the absolute classic sign of a stuck valve which he himself can check in two minutes, look at the position of the flag / lever, call for heat, does it move...

 

[Johntheo5]

Re stuck valve, post #4, "With the heating off, pull on that lever, you should feel a fairly stiff resistance immediately when you start pulling it across, then fire up the boiler, ensure heating thermostat is calling for heat, there should now be no resistance when you "pull" the lever." can easily prove this. The boiler will cut out on own thermostat very rapidly if there is no or very poor circulation due to no water or a blockage or the circ pump not running.