Baxi combi boiler ch problem

[Zehroni]

the DHW is working without any issue but the ch is not. when there a demand for ch, the central heating orange light idslit on the boiler, and the pump is working but no flame and no circulation. what could be the reasons?

 

[CBW]

Which Baxi combi? There’s been a few

 

[Zehroni]

this one

 

[CBW]

Try turning up the boiler temperature control second dial from left hand side

 

[Zehroni]

just did, and set up the wall thermostat trematurid to 30, the temperature inside the house was 19 and boiler still doing the same; the ch light is lit on the temperature control the flame is also on briefly but none of the radiators get warm.

 

[ianmcd]

have you mistakenly closed one of the isolation valves underneath the boiler, post a pic of then and we will tell you, it is a common problem when someone tries to top up the pressure on that boiler

 

[Zehroni]

I do not think so but here is a pic

 

[ianmcd]

They look correct, but those plastic valve levers have a tendancy of splitting and dont actuallt turn the valves, the two outer most valves remove the small srew and pull the lever off and you will see if the valve has actually turned, if the lever has worn just turn the valve with a small adjustable or a pair of grips

 

[martyndc88]

What does the display show when it's calling for heat? Are all your rad controlled with trvs that are set to low?

 

[Zehroni]

do you mean the blue and the black ones that are located inline on the same pipe

 

[Zehroni]

What does the display show when it's calling for heat? Are all your rad controlled with trvs that are set to low?

the display show the temperature which is 90 degrees and keep fluctuating between 90 and 88 however, as soon as I open the hot water tap. I get very hot water, (you can not even touch it) for few second
all the rad have normal control manually operated and all open, no trvs

 

[CBW]

Sounds like a circulation issue. Possible pump failure or dirt/debris in the system.

 

[martyndc88]

Of the hot water is working okay then that rules out the pump. Diverter valve or Blocked return filter

 

[Zehroni]

there is filter in the system in the system which I did bleed today. there is a lot of black stuff came out. see pic. this might be block. how do I check whether or not the diverter valve is faulty.

 

[martyndc88]

Time for an engineer to be called out I'm afraid