HOT WATER RUNS COLD - Is it cos I'm a girl Im gettin no joy?

[monkeybeepbeep]

I've just bought a new flat and for the first month or so I could have a shower/bath fine (mains shower not electric) but all of a sudden if the water is turned on full power it runs cold after about 30/40 secs.... This appears to be happening with all the hot taps but is more problematic with the bath as this is where you tend to run the water on full power more.... If I run the taps slower I can get hot water fine but just means I can't have a shower and it takes forever to run a bath.

I have an ariston eurocombi (A/23 - A/27) about 6/7 years old from what I can tell. I had this serviced shortly after I noticed the water problem. The engineer replaced some switch (not sure what its exact name is - says APS GG8484 on receipt). The boiler had seemed to be continually re-lighting so whatever he did it solved this problem but NOT the hot water running cold. He told me "nothing could be done re: the water problem as this is common with all combi systems" I tried to tell him that the water had been fine the month before but he blatantly ignored me and said id have to trickle the taps to get hot water!

Is it a case of i'm a girl so tell me any old mince...... HELP!?!? I think this is fixable but just need some advice to give me confidence before I get on the the company to complain about their engineer!

 

[ChrisR]

If you can't get about 8 litres per minute of shower temperature water, it's not performing properly - probably needs desludging.
Higher flow rate = cooler water, so a bath will take along time.

 

[Alfredo]

With a combi the boiler only gets 3 or 4 seconds to heat the hot water as it passes through the heat exchanger, so the rate at which you run your tap/shower is relevant, but not necessarily the whole story.

Either, not enough heat is being applied to heat the Hot Water, so he should have checked the burner pressure in Hot Water mode, and made sure the boiler is providing as much power as it says it should on the manufacturers data plate
Or, more commonly, the Direct Hot Water heat exchanger is not as efficient as it should be (they do block quite regularly if the system water is dirty/contaminated), but if your hot water was fine until fairly recently this would seem less likely as the cause.

This is quite general advice, but its impossible to be more specific without being 'on the spot'. Your boiler will have a 'flow rate' which tells you in litres/minute, how much hot water it should produce. This info might be on the data plate, but will certainly be in the manual. If you try and exceed this rate of flow the boiler can't cope and the hot water will turn cold.

hope this helps

Alfredo

 

[monkeybeepbeep]

so if i check the flow rate and it is lower than what the manual states the system can cope with then I need to get an engineer out?

Generally/roughly how much to de-sludge?

 

[DP]

I take it the boiler functions well for central heating; the problem is evident during HW demand only. System needs to be checked to confirm the cause of malfunction.

What your engineer says about the boiler ("He told me "nothing could be done re: the water problem as this is common with all combi systems" ") is not true. He is either pulling your leg/ he does not know/ or does not want to be incvolved. Boiler should give you steady temperature 24/7 should you demand it.

Where in Glasgow are you? I am based in Bearsden

 

[Slugbabydotcom]

Read this in conjunction with other posts as it like them; provides a possible reason for your your problem

There is a Worcester training manual here that is relevant to all boilers. It explains how an undersized gas pipe can cause a serious reduction in winter water temperatures.

 

[ChrisR]

Could also be a problem with the Diverter Valve.
Wait untl boiler is cool, run hot tap and grope the fat pipes under the boiler. If any are hot, you're losing heat from the tap water

 

[Slugbabydotcom]

grope the fat pipes

OO ERR Methinks you should lay off the porno orgy vids