No Hot Water from Gas Boiler

[cdje]

My immersion heater has packed up and left me without hot water. I have had problems with the boiler heating the water since I replaced the central heating pump probably 5-6 years ago, so I need to solve this problem. I cannot get the hot water from the boiler to circulate through the heating coil within the tank. There is a three way valve which allows either radiators, hot water or both. This appears to work correctly but I have also manually moved it with a pair of pliers. No success what ever position will not get flow through the pipework feeding the hot water coil. I thought it may be a air block but opening the breather tube on this circuit lets water dribble out. Any suggestions more than welcome.

 

[kevplumb]

if you have had trouble since changing the pump is it the right way round and is it vented is the f&e tank full is thepump running

 

[Kristoflampie]

Difficult to answer this without seeing how the hot water circuit is plumbed so assuming it worked before and heating is okay. With the pump stopped try bleeding the coil at its highest point which is where the bleed should be, if not slacken a fitting at highest point and see if any air comes out, catch the dribble of water, retighten . With pump on highest speed and on hot water only see if coil heats as this should be an easy route for the flow to take, if nothing check back to see if heat is passing the 3 port valve and check the pump and boiler are definitely running. Basic thing , check the pump has been fitted the right way round so it pumps in the correct direction which is usually towards the 3 port valve, some systems this definitely matters.
Hope this gives you a starting point, good luck