Vaillant ecoTEC plus 418 - Does NOT Work - HELP!!!!!

[Deleted member 105431]

f23 is crossed f&r, easily checked by swapping wires to ntc's. s53 is poor flow/high temp differential.

 

[Agile]

I think you mean reversed pump flow as the boiler cannot know which is the "flow" and the "return".

It needs to be checked on startup from cold as previously requested to see which pipe gets hot first!

Tony

 

[Deleted member 105431]

I think you mean reversed pump flow as the boiler cannot know which is the "flow" and the "return".

It needs to be checked on startup from cold as previously requested to see which pipe gets hot first!

Tony

the 400 heat only boiler does know which is flow and return as the ntc's are wired into the pcb via a harness, therefore the software expects the flow to heat up quicker than the return. on an open system the pump can be flowing in the correct direction but the pipes may be crossed at the boiler which will trigger an F23 fault.

This is a common installation fault, on the older boilers this wasn't too much of an issue.

 

[Agile]

The boiler knows which way the water is flowing inside the boiler.

It does NOT know which of the pipes connecting on to the boiler has been designated as "flow" etc. but then there is also the question of which way the pump is pumping as well.

As previously asked its a simple user task to see which pipe gets hot first at the boiler. Simple to do but difficult to get her to actually do it and tell us!

The tenant seems to have gone away for Easter!

Tony

 

[sheilamurphy13]

Sorry guys, have been pressing buttons and trying to download boiler installation instructions. Took forever to update my Adobe to be able to read it. It says F.23 is "Water shortage, temperature difference between flow and return NTC too large". Possible causes: "Pump blocked or defective, pump output too low, flow and return NTC interchanged" (I have no idea what a NTC is!) So sounds like most of you were on the mark -ish.

However, now i have a far bigger problem now as it is now displaying F.73 (which is not in the installer instructions. It won't fire up at all now, totally and completely DEAD!!!!

 

[sheilamurphy13]

Oh yeah, i would have checked to see which pipe got hot first but they are both stone cold due to new error which i can't seem to override and get some heat.

 

[mogget]

Try turning off the electrical supply to the boiler. Leave it for a minute or so then turn it back on, then fire up the heating.

 

[sheilamurphy13]

I have tried that, several times. No joy though. When I turn it back on F.73 instantly shows, I keep trying reset/flame button - nothing happens but F.73, F.73, F.73 again and again and again

 

[davebgas]

You need an RGI

F73 fault is an "Error in water pressure sensor"


Interruption/short-circuit of water pressure sensor, interruption/
short-circuit to GND in supply line to water pressure sensor

 

[Agile]

Actually F73 on pressurised system models ( which yours is not! ) is "low water pressure" and not the same as the lack of movement when the pump starts which is F75.

Edited to avoid confusion!

Tony

 

[davebgas]

That fault information is para-phrased from Vaillant not my words

 

[Agile]

The 418 is designed for open vented systems!

It should never give F73 codes if all is well and correctly set !

My assessment is that the PCB may not be correctly configured under S93 to be an 418 model !

We need the boiler bunny to confirm this!

Tony

 

[davebgas]

Don't mean to sound patronising to the OP but it does definately say F73??
As Tony says and which I flicked past is is if this on an open system then this fault shouldnt even be a factor... Only reason I asked is had a customer swear blind and called me worse than anything when I questioned her saying her WB 523i was giving an 'ER' fault..... turned up, yep it was EA!!! stupid bint.... still swore it was ER.

 

[Agile]

She has said its an F73 FIVE times in two postings.

Unlikely as it seems, I am inclined to think that its probably saying that!

I know just how annoying it is to be given false information.

Just yesterday, I went with the appropriate PCB to a "Potterton 80E" with a likely PCB fault only to find it was really a Potterton.....

Tony

 

[davebgas]

based on the assumption that the boiler is showing this weird fault when it probably shouldnt..... and accepting the OP isn't as numb as my aforementioned customer..... I'll stump a proposal that is along the same lines as the fault on the sealed system..... the system is full of water isnt it??? Otherwise I'd be looking around the PCB and checking the boiler was properly commissioned/set up as there seems to be problems from the outset