central heating

[dannynasir]

Hi Guy's
Hope someone can help
My boiler fires up and heats the water, only when water in the hot water tank goes below a certain temperature,then if i pull the lever on the diverter valve to manual override my radiators get hot.but as soon as the water is hot enough (i assume it reach's it's temp) then everything goes dead,no power at all to the boiler and nothing i do will turn anything on, until the hot water in the tank gets used and lo and behold the power comes back it fires up on its own, heats up yhe water and goes dead again.
any idea's most welcome.
Tkanks

 

[gas4you]

Not really enough info for us, but assuming it is a 3 port valve you are manually opening I would suspect the microswitch in the head is gone. Try replacing the actuator head only.

 

[dannynasir]

Hi
it is a 3 port valve, when you say change the actuator do mean the motor or the complete top half of the valve. i.e without the valve so i dont have to drain down? sorry if that does not make sense.
thanks

 

[Agile]

If the motor has failed you can often change just that but if the switch has failed you can change the head only with no wet work as long as its a type which can be changed!

Tony

 

[dannynasir]

hi
mine is a honeywell 3 port no. V4073A1039. can you get actuator heads
separatley for them or will i have to buy a complete valve.
thanks.

 

[dannynasir]

hi
mine is a honeywell 3 port no. V4073A1039. can you get actuator heads
separatley for them or will i have to buy a complete valve.
thanks.

 

[Symptoms]

Danny - replacement heads are available for your V4073A (expect to pay up to £50). Older style valves in the range don't have this replacement head feature but you can get an adapter plate assembly which'll upgrade the valve body to take the new head. From memory the 'old' head mounting plate has 4 fixing screws & the new one 2 (or it might be the otherway around). Anyway, all the kit is available from a decent plumbers merchant or mail order from BES.

 

[gas4you]

If yours has a small 'pimple' on the top one end then the head can be changed. Simple job but write down what coloured wires go where before removing the old ones

 

[dannynasir]

hi again
fitted a new actuator head------- still the same problem.
i will try yo explain the fault in detail and i hope somebody can please help me before the cold sets in.
i had a basic old boiler that did the heating and the hot water, i thought i would be clever and get a new boiler fitted a couple of years ago and had a vokera synergy 29 which is not a combi and that has worked fine until now.
now what happens is the display lights on the boiler go off as if there was no power to the boiler BUT as soon as the wife has a bath the water goes cold and the boiler lights up and heats up the water, when the water reachs the temp. set on the hot water thermostat all lights go off again.
now whilst the boiler IS working i can pull the lever on the diverter valve and stick it into the manuel position the heating will work as long as the water is being heated, but as soon as the water is hot enough all display lights go off.
initially i thought there was no power to the boiler so i checked the live at the isolation switch by the boiler and when the switch is OFF i have power going in, but when i switch it ON i dont have power. (i am only using a mains tester)
i still have the old heating and water control panel fitted which has been set to water and heating 24 hours a day and i was using the timer on the boiler to control the heating.
so now i am thinking it might be the control panel.
thank you for taking the time to read this and i hope you understand what i have written and it makes sense.

 

[gas4you]

May sound ridiculous, but have the permanent live and switched live been wired in reverse?

 

[cjb1971]

do you have a room stat?

 

[gas_man_gaz]

try the cylinder stat, it may sound daft but power needs to travel down the satisfied wire for the heating to come on.. just a thought as ive had the same fault b4

 

[dannynasir]

i would imagine the wiring is correct as it has been working ok up till now.

have a room stat but since the boiler was changed it wasnt wired up by the installer to the new boiler so i have not used it since and everything worked fine up till now.

i thought the cylinder stat was ok as i can turn it up and down and the boiler fires up to heat the water when i turn it up, but for what its worth i can try a new one and see what happens.

thanx for you responses any other suggestions most welcome.

 

[gas_man_gaz]

let us know how ya get on

 

[gas_man_gaz]

did it sort then????