Potterton Promax HE Boiler question

[Fats25]

You have to bear with me here as I do not really understand plumbing and heating.

About a month ago (approx when clocks went forward) we have found that on a Friday there is no hot water when we have woken up. First thing I did was check the timer in the kitchen, and all looked correct. Second thing I thought was that cleaner is pressing something when she comes in on a Thursday.

As far as I can tell there are 4 main components to the heating/water:-

A Potterton Promax HE boiler in kitchen
A Thermostat in hall
A panel for timer in kitchen
a Tank in airing cupboard

To resolve the Friday heating issues, I have been pressing the reset button on front of boiler. After checking water is "on" on timer panel. Has all worked ok - have to wait a while for water but does work. However from last night, again with water "on" - the reset trick is not working. Boiler is kicking in randomly (I can hear it) but not immediately after reset trick. Not sure if actually got any hot water - will find out when Mrs gets up in an hour or so.

I am guessing that I will need to get someone out to look into this. Anyone recommend someone in the West Malling area that could assist without raping me? Or is there something simple I am missing here I can check myself?

Now a stupid question - I think I have an immersion button by the tank. At least that is what I have always thought it was. How does this work? Does it work like a big kettle? i.e. I press the button and it electrically heats "filaments in boiler" and then the water in the tank. Or am I completely wrong, and with no boiler, then I have no way of heating the water? I'm going to try pressing the button anyway and see what happens!

Any good advice gratefully received.

[Ferg]

An immersion heater is just that..and immersed heater. Yes, like a big kettle.

[Fats25]

Thanks Ferg for the answer to the idiot question!

A bit more info - before I flicked the immersion heater on, i decided to test to see if I had hot water. I did. After I had tested hot water - the boiler kicked back in again.

Would the tank have a thermostat on it? Perhaps the reason the boiler was not kicking in last night, and this morning when I tested, it was because the water in the tank already had water at a hot enoough temperature. Does that make sense?

It is possible that I am back to the original problem - i.e. the boiler works, but for some reason is not kicking in every time the water is set to come on, without me doing a reset of the boiler. This problem is intermittent.

[Northern Chimp]

A chap in work had the same problem last year - he replaced the PCB at a small cost (did the work himself). He also said to power if off from the mains then re-set the timer etc as it could just be that.

He sent me this, it looks the same problem http://www.howtomendit.com/answers.php?id=7006

[Ricky_M]

Yes, the cylinder does/should have a thermostat. Check that it isn't set too low. Should be on the front of the cylinder somewhere.

If it is not heating the water, it is possible you have a fault with three port valve/ zone valve.