no hot water - system boiler

[stuartmorrison]

Hi,

first time poster so go easy on me!

I have just installed a towel radiator in my bathroom. I have cut into the central heating system and the towel radiator is now the highest point on the radiator circuit.

To cut in I had to drain the system down.

The system was then filled back up with no problems. I bled all radiators under gravity from the bottom to the top. No problems.

I cannot get any hot water from now (either running hotwater only or hotwater and heating)

My hotwater system is a gravity system. I have split the inlet and the outlet connections from the primary coil in the cylinder and seen a good flow of water coming from each connection, however still have no hot water.

I am running out of things to try. Any one got any ideas.

Thanks in advance,

Stuart

 

[Gas2Air]

Stuart, read FAQs and by this i mean..wait for it..What boiler do you have? Etc Etc. Anyway, is the boiler igniting upon demand? It may have gone to overheat and tripped the saftey stat or knocked off pilot?.

 

[stuartmorrison]

HI,

1. My boiler is a baxi bermuda back boiler (installed in 2003)

2, It is connected to a vented hotwater system (2 tanks in attic and a hotwater cylinder)

3. The boiler is lighting briefly on hotwater and then extinguishing as the thermocouple comes up to temperature (this indicates no flow in the hotwater circuit)

As far as I am aware, the system has a circ pump for heating and is gravity circulated for hotwater

Thinking about it I have 2 possible causes:

1. Air in primary coil caused by draining the system down and refilling

2. The primary coil is blocked with crap from draing the system down

I think air is most likely, but I have bled the system repeatidly and have still not managed to get hot water flowing.

There are no bleed valves on the hot water system, so I have been extracting the air by cracking the compression fittings on the coil inlet and outlet.

Stuart

 

[possum_jenkins]

How long does the boiler stay lit for before it goes out. Have you checked the coil pipework to see if it is getting hot before the boiler goes out?

Have you bled the pump?

The main flame going out indicated demand satifisied. The thermocouple does not heat up per se, it is a safety device.