Tap symbol always on Vaillant 637 system boiler

[arh]

I have noticed that the tap symbol (solid not flashing) is always on my boiler screen even when the boiler is off. Is this a problem? Everthing is working fine. System with unvented unistor cylinder. Could these be a motorised valve issue? System is 7 years old. Last year the motorised valve was replaced.

 

[simond]

Doubt if you have 937, that is a combi. 637 more likely.

 

[arh]

Yes sorry it is a 637.

 

[simond]

Were you standing upside down?

How do you control this unit, do you have a Vaillant controller (which one) or some third party controls?

 

[arh]

It is connected via a honeywell 7 daytimer. A while ago the hot water zone valve was replaced. Could this be wrong wiring issue? Even with the boiler off the tap symbol remains. I am concered that the water may overheat the cylinder if it is permanently heating the water all of the time. I do not think that this was the case before.

 

[simond]

Is the boiler on all the time?

The early 637 had a tap knob on the facia and a tap symbol. The former is not used in your configuration, the boiler is only on when the rad symbol is shown on the display, when either HW or CH is on, or both.

 

[arh]

Yes you are right as the hw temp knob does nothing. Thank you for the confirmation. Glad to know that I can ignore the tap symbol.