Old back burner Gas Boiler Fault

[steve121]

Hi all,

I really hope someone can shed some light on my Central Heating fault, the reason I ask is so I can save some money as possibly do the job myself.

My boiler is atleast 15 years old and should be replaced but a new boiler is very expensive so this will have to wait.

The problem I have is that when the hot water heats up in the hot water cylinder storage tank to the required temp the boiler then stops untill the water cools down, this is expected.

But the problem I have is that my central heating is also connected to this system and when the boiler stops my heating will also stop. During the winter months we all need heating for long periods of time.

What is the fault, that also causes my heating to also stop or could there be a common part that needs replacing.... Please help

 

[adlplumbing]

check your time clock and three port your clock may need upgrading
to allow this to be done but without looking i can`t really comment further

 

[Gasop]

Check that the pump is running when the room thermostat (if fitted) and programmer is calling for heat.

 

[tdesnos]

take the head off the three port valve and manually close it. then run the cylinder off the immersion and use the bopiler for ch only. then when you've got some pennies get a new boiler

 

[adlplumbing]

take the head off the three port valve and manually close it. then run the cylinder off the immersion and use the bopiler for ch only. then when you've got some pennies get a new boiler

or better still turn of gate valve too cylinder

 

[steve121]

Thanks all,

really appriciate your advise, I have actually replaced the 3 port motorised valve and it seems to have done the trick, the old valve could not have been working as it should.

The only problem being I have got a lot of air in the system. I have refilled all the rads and taken out the air but I have also got air into my back boiler.

So what it is doing now is heating for a few minutes and then overheating and switching off, I have tried everything to get the air out the boiler but nothhing seems to work.

Any suggestions, please help

 

[Hugh Jaleak]

Put the valve in the manual position when filling, this should assist with escape of air as system refills. From your description it sounds like the pump may not be moving the heated water from the boiler adequately. Have you bled the pump? (Open big silver screw in head of the pump until water dribbles out, then retighten.)

 

[kirkgas]

check the pump has no air in it and is actually spinning, remove the big silver nut on the front of the pump and see if the impeller is turning, it is unlikely to be air in the boiler if the pump runs it will push the air out into the system which you will bleed from the rads

 

[Ronald0]

You have bled the rads but have you bled the primary (hot water) circuit?

Is there a coil upstand bleed nipple near the cylinder?