Incorrect wiring? Hot water temperature ignored.

[oliverwgn]

Hi all,

I have got a new Vaillant EcoTec 418 installed recently and noticed that the set hot water temperature is being ignored, instead it gets generated by flow temperature. Also diagnostics menu says that DHW hours are 0.

Could this be a result of an incorrect wiring? I'd like to set DHW and radiator temperatures individually.

System is sealed, which has a Megaflo CL145S tank with 2 electric valves and 1 pump controlled by a 2 channel Wiser room thermostat kit.

Thanks in advance.

 

[DP]

Does the valve for HW zone open when HW channel is calling.
does the boiler fire?

 

[oliverwgn]

Boiler is working fine and both zones are opening / closing as expected, the only difference is that the set HW temperature got ignored.
Please note that the previous boiler had only 1 temperature setting for both hot water and heating.
Thanks.

 

[polesapart]

On the 4xx series the HW dial on the boiler fascia has no function except when certain Vaillant proprietary external controls are used.

 

[Mister Banks]

Hi all,

I have got a new Vaillant EcoTec 418 installed recently and noticed that the set hot water temperature is being ignored, instead it gets generated by flow temperature. Also diagnostics menu says that DHW hours are 0.

Could this be a result of an incorrect wiring? I'd like to set DHW and radiator temperatures individually.

System is sealed, which has a Megaflo CL145S tank with 2 electric valves and 1 pump controlled by a 2 channel Wiser room thermostat kit.

Thanks in advance.

What you want to do can not be done with Wiser controls, you will need Vaillant controls.

 

[oliverwgn]

I see, so DHW can only be controlled by a Vaillant thermostat which communicates with the boiler via ebus?
Wondering if there any converter available for 3rd party controllers which can emulate this function

 

[CBW]

I see, so DHW can only be controlled by a Vaillant thermostat which communicates with the boiler via ebus?
Wondering if there any converter available for 3rd party controllers which can emulate this function

Tado I believe support similar. Stored hot water should be kept at a temperature of 60-65 degrees, what are you trying to achieve?

 

[oliverwgn]

Thanks for the tip about Tado.
The previous boiler has aged out / died, so I tried to get one with individual temperature controls for DHW and radiators. The plan was to keep hot water at 60°C and rads on 55°C, but I understand if that's not possible.

 

[CBW]

Thanks for the tip about Tado.
The previous boiler has aged out / died, so I tried to get one with individual temperature controls for DHW and radiators. The plan was to keep hot water at 60°C and rads on 55°C, but I understand if that's not possible.

I don’t 100% know if it’s possible, I’d say not. However you can range rate the heating load.

 

[oliverwgn]

I'll take a look on them.
Yeah, I've set it to 60°C. Not much of a difference, but it would have been nice to use the function if the boiler supports it.

Thanks everyone for your replies, it helped a lot.