Vaillant Ecofit Pure Target temperature too low

[Andrew Edmondson]

I recently solved a problem with the DHW on this boiler, with the help of some members here.

In doing so, I replaced the diverter valve, pressure sensor and eventually the main board.
It turned out that the replacement pressure sensor was also faulty. Problem solved. Great hot water.

As soon as I had finished, the central heating target temperature D.005 is constantly at 40C.
I replaced one of the temperature sensors but have the same problem.

I can post all of the D code readings if necessary (I've written them on the manual pages).

There is a simple remote relay thermostat.

TIA

UPDATE: D.005 target temperature is now 18C.

 

[CBW]

Is this a combi boiler, heat only or system? What age Vaillant?

 

[Andrew Edmondson]

System boiler, 830, combi, 3.5 years old.

 

[DP]

Megnatron valve cannae take it captain.
Lot of defective parts on that boiler old chap. There is me thinking Vaillant was a good make

 

[CBW]

Have you tried adjusting the value on the front of the boiler?

 

[Andrew Edmondson]

D.71 at 65C

 

[CBW]

Not entirely sure then. Definitely not an ebus controller?

 

[Andrew Edmondson]

No ebus or exterior sensor.
No F codes.
A real mystery

 

[CBW]

A real mystery

@ScottishGasMan might be able to assist you further (tagged in so he’ll see it). It’ll be interesting to find out why it is.

 

[Andrew Edmondson]

 

[CBW]

?????????

 

[ScottishGasMan]

I'm not comfortable giving advice to a DIYer who seems out their depth touching gas equipment.





Best bet is to call a gas engineer familiar with these boilers or fixed price repair from manufacturer.

 

[Andrew Edmondson]

I understand but I'm a DIYer of 40 years and am not modifying the gas side.
I'll perservere on my own.

 

[ScottishGasMan]

Opening the front casing is disturbing the room sealed casing immediately needing full 26.9 gas checks completed after and a PCB is a saftey control

 

[Andrew Edmondson]

OK problem solved. I forgot to look at the consumer radiator temperature setting!

That sort of advice would have been helpful.

I won't be using this forum for plumbing advice anymore though.