Vailant ecoTEC plus 624 problem

[Geoff1]

Hi

I have a Vailant ecoTEC plus boiler less than 1 year old. It has started making knocking noises occasionally, accompanied by a Status Code S.53. Otherwise operation is fine.

The installation guide says this means 'appliance is within the waiting period of the operation block function due to water shortage (VL-RL spread too big)'. The system pressure has been checked at about 1.5 bar,

Could anyone explain what this means, what is VL-RL, what is likely cause etc.

Many thanks

 

[simond]

I would check the internal air vent is open and the internals of the boiler are not melted due to a failed HEX seal.

Assuming your boiler was professionally installed and Gas Work Notified I would imagine you have 12 months warranty in hand and possibly a free service visit to inspect the seal?

The boiler will be coming up for its annual service anyway - you need to do this to keep the 2yr warranty.

 

[simond]

Just noticed its a 624.

Do you have a large no of rads? Are your rads high water content eg: designer tubes etc?

Do you need to repressurize more than twice in 12 months? Could have an undersized expansion vessel.

 

[gas4you]

Seems like another Vaillant mis-print in the installation guide

S 53 is actually when it is in a 20 minute waiting period because a lack of water has been detected.

The actual code for for what you have written is S76.

Was the system correctly power flushed and cleansed when it was installed? I would suspect a blockage in the pump preventing it from circulating correctly. A pump fault can also give a low water fault code as well and this would fit in with the banging you sometimes hear.

Check as Simon says that the auto air vent is loose as an air lock could also give rise to the boiler thinking it is low on water.

You could try re-purging the boiler/system. Turn off on boiler and whilst turning back on press and hold the + button until P0 appears, then press 'i'.

It will then run through purge process, takes about 5 minutes or so.

 

[Geoff1]

Hi

Thanks for your replies. It would seem that a 'water shortage' is the key which could perhaps be explained by some sort of blockage or flow problem. Another source has clarified that the VL-RL spread refers to the Flow and Return differential temperature. The system was power flushed before installation of the new boiler but maybe some silt has remained which is causing a partial blockage. The overall radiator capacity is well within limits.

I will check the bleed valve anyway. Does anyone know if there is a filter in the pipe work connections to the boiler as if not maybe the system should be flushed out again.

I'll keep you posted on the outcome.

Thanks

 

[gas4you]

Theres no filter on the ch pipe work.

If the flow and return temperatures were out of range or the boiler thought they were you would probably get an F24 fault.

Strangely the VL-RL is not mentioned in the engineers manual supplied buy vaillant.

Have you ever had any F codes displayed yet?

 

[Geoff1]

Hi

I've not had any fault codes displayed.

S.53 to me now implies the differential between flow and return is too great rather than that either one is out of range. Not sure if that was what you meant. It does seem a bit strange that the problem is not regarded as a fault - maybe it's only just out of range ??

Thanks

 

[Geoff1]

Hi

Apologies for not providing an update before but have been on holiday and other commitments. I can report that Fault Code 75 eventually came up - No pressure rise detected on turning on the pump.

I drained the system down, flushed it through with cold water, refilled and the boiler functioned for 1 day but wouldn't restart the following morning. Drained again and refilled with some Sentinel X400 sludge remover. Ran this for a couple of days and then drained down, flushed through and refilled with Sentinel Inhibitor. It's now been running O.K for over a week now so fingers crossed that may have done the trick. Seems the original power flush may not have cleaned sufficiently - it was only run cold through the old pipework/rads.

Regards

 

[Agile]

This makes me worder if it really was a professional CORGI installer!

Anyone else would have been on the phone to the installer getting him to sort it out and complaining to CORGI if they did not!

Tony

 

[gas4you]

F75 is a known fault with the ecotec plus, especially if it is the older orange pressure sensor.

Vaillant will try and maintain it is due to the system not being clean enough, but usually it's just a sensor fault.