boiler not firing when hot water comes on

[andymin1980]

Hi I am on a gravity hot water and pumped central heating system (C Plan I think). I recently upgraded my programmer/timer from a analogue Randall 102 to a digital thermsaver TH-0472-02.

Unfortunately the hot water would not come on with the heating as it is supposed to do without setting the HW and CH times exactly the same. Looking on the internet I thought a Honeywell Wiring centre would be the answer to my problems.

As per the instructions I cut out link 1 (If using a Programmer not basic time clock), and Links 2 and 3 due to being on Gravity based primary system. I dont have a room thermostat so linked terminals 1 and 3 at the room stat connector block (as per instructions) and proceeded to wire in all my components.

Now the hot water turns on with the heating but when going downstairs to look at the back boiler the flame is just sat on pilot and not fired up.

Any help with this matter would be greatly appreciated.

 

[twgas]

you think you have a C-plan, this is where the HW is heated, from the boiler, by gravity but has a 2 port valve and cylinder 'stat so that the HW is temperature controlled. IS this what you have?

 

[andymin1980]

Hi Mick thanks for your response.

I have looked all around my storage tank and unfortunately cannot find a 2 port valve or anything resembling a valve is this normal? Am I also correct in thinking that this would be motorised?

I have an old system in a terraced house consisting of a Baxi Bermuda 401 back boiler which has a dial with 1 - 4 that controls the temperature of the water, also after looking there is no cylinder stat on the storage tank. There is also a pump on the tanks heating outlet. Other than the power I have no other components that wire to the system.

I am coming to the conclusion after another day of messing that the problem lies with me and the type of programmer that I have bought.

After removing the wiring centre and rewiring straight back to the programmer I can get the HW on with CH if I turn CH to constant, other than that I can get both on if the seperate timing programs are set to the same times.

I'm thinking I should have bought a mini-programmer better suited to gravity HW and pumper CH and not a programmer that totally seperates the HW from the CH.

 

[twgas]

check you've got water in the f&e tank (the small one, usually in the loft)

 

[andymin1980]

all seems to be running ok at minute boilers firing up and got hot water and heating. I think problem lies with timer think will look at a Randaill 102E or similar.

Thanks again for response.

 

[twgas]

What makes you think it's a problem with the timer?
Did you check the f&e tank?

 

[slapper]

Hi Mick thanks for your response.

I have looked all around my storage tank and unfortunately cannot find a 2 port valve or anything resembling a valve is this normal? Am I also correct in thinking that this would be motorised?

I have an old system in a terraced house consisting of a Baxi Bermuda 401 back boiler which has a dial with 1 - 4 that controls the temperature of the water, also after looking there is no cylinder stat on the storage tank. There is also a pump on the tanks heating outlet. Other than the power I have no other components that wire to the system.

I am coming to the conclusion after another day of messing that the problem lies with me and the type of programmer that I have bought.


Remember the rule of thumb for gravity hot water/pumped heating is..

You can have hot water without heating but you cant have heating without hot water, not unless you reconfigure your existing set up.

After removing the wiring centre and rewiring straight back to the programmer I can get the HW on with CH if I turn CH to constant, other than that I can get both on if the seperate timing programs are set to the same times.

I'm thinking I should have bought a mini-programmer better suited to gravity HW and pumper CH and not a programmer that totally seperates the HW from the CH.