problem glowworm essential 24c

[Gary80gas]

Just looked at glowwworm essential 24c combi. Only 14months old and out of warranty.
Hot water will only run luke warm.
Temp coming from heat exchanger only reaches about 45c in hot water mode.
Super red hot in heating mode no problems there.
Checked thermistors which control both heating and hot water and all ok.
Went through diagostics with glowworm tech and got the usual change the pcb answer. Any of you got suggestions what else it could be? Thanks.

 

[ShaunCorbs]

What's the lpm out of the hot water tap / does it get hot when you only open it half way etc ?

 

[Gary80gas]

Temp is constant 35 deg luke warm what ever the flow high or low no matter how long you run it. Something is stopping the boiler from ramping up the power enough to raise the temp. Switch to heating and the same primary sensors allow the temp to top 65 deg.

 

[ShaunCorbs]

So there's no hot water temp sensor ?

 

[Harvest Fields]

Have you checked all the parameters?

 

[Gary80gas]

There is no hot water sensor, just primary flow and return sensors, I checked them and there in range hot and cold. If the boiler easily reaches 65 deg in heating what parameters do you check for only reaching 35 deg in hot water mode? The gas valve opens the pump and fan runs but the temperature is limited and remains constant at 35 deg. Apart from pcb, which I always hesitate to change because i've been directed to change pcb's by tech lines and its been something else.

 

[Harvest Fields]

You can set them up in the D codes I believe.

 

[Gary80gas]

I went through d codes with vaillant tech. Everything was either spot on or we upped the figures to higher temp with no effect.

 

[Harvest Fields]

Board then?

 

[Gary80gas]

Yeah, just trying to route out all other possibilities.

 

[Gary80gas]

Told customer to call in vaillant to check boiler as not happy changing board. Took there engineer 5 mins to reset in system codes. Very frustrating, I went through codes with vaillant tech on phone. Everytime it didn't work, under vaillant techs instruction we checked it had saved code changes, what don't they tell us, should be simpler.

 

[Harvest Fields]

Told customer to call in vaillant to check boiler as not happy changing board. Took there engineer 5 mins to reset in system codes. Very frustrating, I went through codes with vaillant tech on phone. Everytime it didn't work, under vaillant techs instruction we checked it had saved code changes, what don't they tell us, should be simpler.

No idea mate. But I have had it a couple of time after a power cut or surge. First thing I do is parameters. I did have one I couldn’t change so changed the board and it worked. Customer was happy. You 100% certain he didn’t change the board?