Vaillant 824/2 - Luke warm water

[Grangey]

hi all,

Have a hot water issue with my Vaillant ecoMAX 824/2 e. (edit, model number updated, originally incorrectly called it an ecotec).

Heating works fine, however when you run the hot water you’ll get a short burst of the correct temperature before it going Luke warm.

Basically turn the showe on, and you can see the temp reading go from a low (say 30degrees) up to about 75oc, before the main burner seems to cut out and the temperture just drops, and drops, until it reaches around 50degrees (not that it feels close to that warm out the shower). It doesn’t seem to attempt to ever re-engage the main burner. Shows “S.14” during this process by the way.

I’ve replaced both hot water NTC’s with genuine parts to no resolution thinking this could be the cause. Anyone have any ideas? Thankfully whilst chilly, I can just about withstand a shower as it’s not stone cold, but obviously want this sorted pretty sharpish!

Thanks in advance!

 

[Grangey]

Update, it seems to be an issue at full flow. Taps which have a water saving filter in, as well as “small” shower heads seem to reach temp and stay. However larger shower heads that worked fine before, cause the temp to drop.

Anyone have any ideas?

EDIT: I was wrong, this also effects the taps too.

 

[picasso]

A 24kw boiler will struggle with the water coming in at 5c to give a half decent flowrate.

 

[Grangey]

A 24kw boiler will struggle with the water coming in at 5c to give a half decent flowrate.

It’s worked fine for 3 years so it’s an issue that’s just started which I’m trying to identify, not something that never worked which would be limited by its manufacturer specification.

 

[Grangey]

Anybody have any suggestions? Been lacking on this recently but getting fed up with luke warm showers.

For clarification this effects all hot water, not just showers.

 

[ScottishGasMan]

You cant work on an ecomax boiler without removing the main boiler front which forms part of the room sealed casing, therefor DIY advice cant be given on the forum for working on that boiler. I suggest getting a qualified RGI to look at the boiler, its normally a fairly straightforward repair.

 

[ianmcd]

with the heating turned off and the heating pipes cold run a HW tap and see if one of the heating pipes gets hot with just HW on

 

[Grangey]

with the heating turned off and the heating pipes cold run a HW tap and see if one of the heating pipes gets hot with just HW on

Thanks! As it happens I tried this last night and CH pipes remained cold/cool so doesn’t seem to be the diverter value. Does this help point to anything else?

 

[Grangey]

You cant work on an ecomax boiler without removing the main boiler front which forms part of the room sealed casing, therefor DIY advice cant be given on the forum for working on that boiler. I suggest getting a qualified RGI to look at the boiler, its normally a fairly straightforward repair.

Appreciate this may be applicable to typical diyers, but that I am not. Also the ecomax 824/2 is hardly in “room sealed casing” as the bottom is far from sealed or air tight.

 

[ianmcd]

Thanks! As it happens I tried this last night and CH pipes remained cold/cool so doesn’t seem to be the diverter value. Does this help point to anything else?

isolate the cold water inlet to the boiler then open a hot tap till it stops running , and turn thermostatic showers and taps to max hot then open a hot tap and see if any water comes out it could be a faulty thermostatic cartridge

 

[Grangey]

isolate the cold water inlet to the boiler then open a hot tap till it stops running , and turn thermostatic showers and taps to max hot then open a hot tap and see if any water comes out it could be a faulty thermostatic cartridge

Thanks I’ll try that this evening. What am would I expect to see when I open the hot tap? No water I presume? So if water comes out it’s the cartridge?

 

[ianmcd]

yes sometimes the cartridge passes cold water into the hot side so the water coming out at other outlets is cool, with the cold water inlet valve to the boiler closed you shouldnt get any water out of the HW outlets

 

[Gasguru]

Appreciate this may be applicable to typical diyers, but that I am not. Also the ecomax 824/2 is hardly in “room sealed casing” as the bottom is far from sealed or air tight.

But you are very much a typical diyer if not worse...swapping random parts, have no idea how the boiler operates and yet think you know better and ignore sensible advice.
If that chamber isn't sealed with the front panel fitted (an approved limit is permitted) you have a serious problem...,failed casing seal, corrosion, gromits missing etc.
We can see from your previous postings that the boiler is not in good shape and has not had regular servicing.

Put the case back on and call someone in....