vailant ecotec 838 combi instaled, on heating mode boiler on limp mode

[max 54]

hi guys,
i had recently combi boiler instaled one of vailant advance approved enginerer.
hot water works fine. on heating mode, boiler starts with full flame and after a second drop to low flame and never reach target temperutre set for heating.
its like in a limp mode, works but like a safety divice activated,
enginer said that its very efficent boiler thats why its like this.
which i dont beive that/
any thought would be helpfull
best wishes

Read more: https://www.diynot.com/diy/conversa...r-on-limp-mode-low-flame.35356/#ixzz6boS9dmHs

 

[max 54]

 

[CBW]

Good evening,

What controls are you using? What’s the temperature set to on the boiler thermostat and room thermostat? Any zone valves installed?

 

[max 54]

Target temperature set for 60
Room thermostat on maximum.
Combi boiler so no zone valve involved

 

[CBW]

Seen plenty of combi’s on zone valves. Do any rads get hot? Do you have trv’s on the radiators? Are you sure the target is set to 60?

EDit: also the link you provided doesn’t work.

 

[max 54]

Radiator get warm Luke warm after a few hours

 

[max 54]

Yes I m sure target temperature set 60 degrees on the boiler,
Tvr valves all open fully

 

[CBW]

I’d be getting the installer back then, something obviously isn’t right, unless you have ebus controller, but even so, should heat up decent enough.

 

[picasso]

Press the top right hand button and post back what s code is showing when the boiler is in limp mode and how many rads do you have ?