Worcester 24i Combi Boiler constantly resetting

[truant]

My 10 year old (but regularly serviced) boiler has developed a problem in that it overheats when we are using the shower causing the overheating reset switch to pop up.

Once the overheating switch is pressed down the boiler fires up and continues on (usually for around 4-5 minutes however sometimes longer).

I have had a heating engineer here and he replaced the pump however the problem remained. He came back and spent ages on the phone to Worcester but still nothing (apart from try to clean the shower head). I did this (it was already clean with no buildup) but the problem remains.

If anyone had any other ideas I would be really grateful!!
Regards
A.

 

[bengasman]

What is the flowrate of the hot water?

 

[truant]

Wow - thanks for the quick response!
The flow rate out of the shower head seems the same as normal. Is there some way of measuring this?

 

[holty]

replaced the pump. whats that gotta do with hot water.

 

[nicknox]

You need to check whether the boiler is modulating i.e. the burner pressure is getting lower as the water temp is increasing. This would cause the above fault. Burner pressures need to be checked. But it could be that theres scale in the heat exchanger.

 

[bengasman]

The flow rate out of the shower head seems the same as normal.

So what is normal?

Is there some way of measuring this?

Measure the amount of hot water only at max flow over a sufficiently long timespan.

And do a gasrate whilst you are at it.

 

[holty]

surely its gotta be a wind up about the heating engineer looking at it.if they couldnt figure out how one of these works in hot water mode. god help

 

[bengasman]

surely its gotta be a wind up about the heating engineer looking at it.if they couldnt figure out how one of these works in hot water mode. god help

Plenty of guys around that do nothing but installing; they don't know jack about how a boiler actually works. Lots of those that have done sfa for months and some will have a go at repairs.

 

[truant]

I really wish it was a wind up... I am already £150 pounds out of pocket replacing something that didn't need replacing! I have no idea about these things and that is why I got an engineer in.

Thank you for all your advice but I am a little confused:
1). How do I check the burner pressure?
2). To measure the amount of hot water only presumably I have to collect it (say in buckets) for a minute or 2 then work out the litres per minute?
3). How do I check gasrate?

Sorry if these questions are stupid but all your help is appreciated...

 

[holty]

id love to see the guys face if he came across an old vaillant or something,then the customers when they get the bill

 

[holty]

if i were you id demand your money back, its like a mechanic putting in an engine when its the wheels that need changing. sorry i was typing the last post after you made yours. sounds like youve been had.

 

[truant]

Possibly the even scarier thing is that I was in the room when I heard Worcester recommend this course of action to him.

I am gathering from what you are saying that the pump only has something to do with the central heating and not the hot water?

 

[bengasman]

... To measure the amount of hot water only presumably I have to collect it (say in buckets) for a minute or 2 then work out the litres per minute?

That's the ticket

How do I check gasrate?

When you look at the meter, is there a little dial that goes round when the boiler is on, or only turning numbers with the last three in red?

 

[truant]

OK - I have measured the flowrate and it is very close to 6 litres a minute of hot water (though a mixer valve).

The gas meter has a little red dial that goes around when the boiler is on.

Once again - thanks for taking the time to help me out.

 

[truant]

OK - I have measured the flowrate and it is very close to 6 litres a minute of hot water (though a mixer valve).

The gas meter has a little red dial that goes around when the boiler is on.

Once again - thanks for taking the time to help me out.