hot water problem with LS80 (white star)

[kingy666]

Hi all, i could do with some advice before i call out an engineer. I have a Ravenheat LS80 A K A white star/silver star, i have started to have problems with the hot water. sometimes the hot water will not work at all, pump does not start- no fire up- nothing. other times the bolier will fire up and run for 30 seconds, the water gets hot, maybe a little too hot and then the boiler stops for a few seconds the water runs cold and then it will fire up again. the red overheat light doesn't come on but while the boiler is running and i am getting hot water it sounds like water and air is going through the pump. this happens even if i turn the h.w. potentiometer right down or right up. could this be the potentiometer or the h.w. sensor.

any help is much appreciated.

 

[Agile]

Its possible the auto air vent cap is tight. You can check that its just loose.

The hot/cold water is a symptom of dirt in the plate heat exchanger and is because the installer did not flush the system properly before fitting the boiler.

If its under the guaranty then it might become a chargeable call if you call Ravenheat as its not their boiler's fault.

Tony Glazier

 

[kingy666]

Thanks Tony, i have checked the auto air vent and it is fine. i do know that the man i got to install the boiler only flushed the system with water-- is this correct. I have since used killrock central heating cleaner, which i left in the system for a couple of weeks before flushing out with water a couple of times before adding killrock central heating protector. All the pipework to the central heating was installed by myself using pushfit connections except for the connections within a couple of meters of the boiler which are soldered. this ,i think, should greatly cut down the possibility of solder getting into the heat exchanger. do you think if i used the cleaner again this could help.

 

[Agile]

I have never heard of that type of cleaner.

Much better to use Sentinel or fernox quality products!

If all the rads were new then its difficult to know quite what may be blocking the HE ( assuming thats what the problem is ).

New systems often give very bad blockages if they are not properly cleaned. What was the colour/texture of the water that came out?

I have seen all sorts of blockages, wire wool, brick dust etc. even a fuse!

Sometimes even new rads have a lot of rust inside them.

Tony

 

[kingy666]

when i flushed the system the water was only slightly brown. this c.h. sytem and boiler has only been in for around 8 months.

 

[Agile]

It should be clear with perhaps just a touch of "straw" colour!

Tony