Hot water for 20 seconds - then lukewarm

[frippet]

Hello all - I need help, please.

We have just moved in to new place and are trying to figure out our boiler. The heating and timer works well, but we've had to fill up the pressure a bit. We get very hot water, but only for a very short time - then it goes lukewarm and stays like that untill it is turned off. Does anyone have an idea what it can be?

It's an Ariston Euro combi - don't know how old. The property has been empty for 5 months, but the timer has been put on to heat a couple of times a day throughout.

Any advice appreciated.

- Frippet

 

[Agile]

With so little information available all I can suggest is there is dirt blocking the plate heat exchanger.

If you are regularly topping up it implies a leak and that will be the cause of the dirt even if the system was cleaned before the boiler was fitted.

Tony Glazier

 

[frippet]

Thanks for your reply. What sort of information would be needed to get a better idea? What shall I look for to explain what is wrong?

Cheers again,

Frippet

 

[Polly1]

I would also try turning down the tap a little to see if the water warms up at a slower flow rate. Your boiler may have the flow rate set to maximum which might allow the water through too quickly & therefore not allowing enough time to heat it as it passes through the boiler.

If your water is hot when the tap is turned down a little, finding the instructions for the boiler would be the next best step so you can adjust the flow rate.

 

[frippet]

Thanks for your replies. We definitaly have a leak as the pressure drops on a daily basis - the previous owner said he had to top it up once a month, but we've had to do it almost everyday. So we have now called an expert to come and have a look at it (oh, the joys of extra and unforseen costs when buying).

The guy we have called has come recommended by my uncle who has dealt with him several times and says he's reasonable, but how big a problem IS "cowboy" boiler repair men really?

And does anybody know these things can cost (I know it's difficult to say when we don't know what's wrong, but say it's a leak and the flow).

Again, thanks for your help.

Frippet

 

[Agile]

"""The guy we have called has come recommended by my uncle who has dealt with him several times and says he's reasonable, but how big a problem IS "cowboy" boiler repair men really? """

I would say that its not a big problem. A much bigger problem is a lack of proper diagnostic skills amongst people offering to repair boilers.

The TV rogue trader shows are solely for entertainment. They intentionally trap firms who are already known to be dogey. Showing 49 firms honestly fixing boilers has no entertainment value. So they call the one in 50 they know are going to provide entertainment.

Tony Glazier

 

[frippet]

I would say that its not a big problem. A much bigger problem is a lack of proper diagnostic skills amongst people offering to repair boilers.

The TV rogue trader shows are solely for entertainment. They intentionally trap firms who are already known to be dogey. Showing 49 firms honestly fixing boilers has no entertainment value. So they call the one in 50 they know are going to provide entertainment.

Tony Glazier

he-he.. point taken! I did, however, read a long survey in Which! magazine that stated that even "proper" British Gas people etc quite often gave wrong advice and overcharged. But I suppose that's how Which! makes it's money as well...

 

[Softus]

Any advice appreciated.

More information would be nice, but so far this is consistent with one or more of the following:

1. Burner pressure too low.
2. Faulty gas valve.
3. Faulty modulation circuit on PCB (resulting in GV not energising fully for DHW).
4. Stuck divertor valve.
5. Faulty wax capsule on DV.
6. Faulty DHW temperature sensor.
7. Faulty sensor circuit on PCB.