s 53 code on Vaillant Boiler

[Bouba]

Hello everyone,

My Vaillant boiler keeps giving s53 code, and keeps cutting out and starts again every 3-5 minutes.

I called an engineer and he cleaned my heat exchanger and quite a bit of black metals came out.He said that this is the reason why s53 would be caused as it has a blockage somewhere
However after few days the problem started again for the fault code.The manual says that s53 is caused by lack of water,but the water is on 2 bar.He also installed magna-flow on the return pipe.

After trawling the forum and internet i have had no luck.Water works fine and the radiators in the house are all lukewarm,but not hot.I am wondering if someone here is could tell me if i need another engineer,or will the problem sort itself out after few days.Boiler has been running on for 24 hrs now non stop.

I am wondering if it is being caused by the capped off pipework in the new extension,which was meant to be for the radiators as the engineer has not picked up on this.I have not had a chance to get them fitted.Basically the flow and return pipe have been capped off separately only for 2 radiators.Would this cause s53 error code.Should the sealed heating system have a continuous run of radiators or would this result in the issues i am having.
Thanks.

 

[Dan Robinson]

Plenty of information on this forum about s. 53


Take it you have a 4 series Vaillant?

 

[Bouba]

Hi,
The vaillant is turbomax plus 828e

 

[Gasguru]

S53 on a Turbomax is an unusual status code.
The boiler software is monitoring the temperature drop across the main heat exchanger and burner input and isn't happy with the results.
Whatever you do don't top up the pressure more than 1.5 bar otherwise you risk creating further problems with too much pressure when the system is hot.
I'm guessing the secondary heat exchanger was cleaned out. Was the pump checked at the time.
Is this fault just on heating, just on hot water of both modes?

 

[Bouba]

Thanks Gasguru.Yes the secondary heat exchanger was cleaned with some chemical and was left in it for 45 minutes.Loads of black metal gunk came out.The engineer also installed magna filter on the return flow pipe.

He did remove the panel which has fire behind it,and cleaned with a brush.

I am not sure if the pump was checked at the time.The engineer just said pump is fine,not sure if he removed it.It is a black grundfoss pump.
Hot water is fine.It only happens with heating only.

"Is my opinion on radiator not connected to the new pipework which have been capped causing this code valid or baseless."

 

[Gasguru]

I don't think your pipework is causing the problem.
There may be some partial blockage in the heating circuit but it might be worth range rating the boiler...ie. to set the Kw power output to match the actual heat load of the radiators.
This is rarely done on installation but will let the boiler run with better control and may solve the S53 issue.
You'll need to call someone in as gas pressure need to be measured during the process.

 

[Bouba]

Thanks.I would preferably like to call another engineer rather than the first one.
The boiler is rated at 28kw.

I have a total of 8 radiators installed at present with 2 still to be installed.Am i able to range rate the boiler without doing anything which needs a gas safe engineer.This might help

2 x radiators : 1600 long x 500 tall : type 22 Double panel
3 x radiators : 1200 x500: type 21 single panel
3 x radiators: 800 x 500 type 21

The other 2 radiators which are still to be installed are bathroom towel radiators.

Is here a decent engineer on this forum in essex/redbridge area who can service and sort vaillant boilers.

I have already spoken to agile and he is not covering this area.