Ravenheat error code 28

[Andrew Gower]

I am getting the error code 28, if i bypass the flue sensor with a bit of wire the error goes away and the boiler works, so can i assume the flue sensor if faulty? If I do a continuity on the sensor there is none, should there be? I did buy a replacement on ebay and fitted it, the code did not go away and also there is no continuity over the new sensor so would that be faulty also?

 

[Agile]

Ravenheat boiler model might be useful!

I am sure they made more than one model !

 

[ianmcd]

Doesnt matter which Ravenheat you have stop messing around with a safety critical part

 

[Andrew Gower]

Ravenheat boiler model might be useful!

I am sure they made more than one model !

HE120T Low Nox Condensing Boiler

 

[Agile]

You have spoilt my fun.

I was hoping to find out what he was doing wrong with his continuity measurements!

 

[Andrew Gower]

You have spoilt my fun.

I was hoping to find out what he was doing wrong with his continuity measurements!

So if i put a test on the sensor should there be continuity?

 

[Agile]

Well Andrew we are not permitted to give advice on gas or combustion aspects to DIYers. You should not have even opened the boiler casing as its a room sealed unit.

I don't see why you were looking at the flue sensor. F28 seems to relate to the water pressure switch!

Usually just needs water pressure topping up but on a dirty system the switch entry can get blocked with sludge.

The flue sensor is not a switch. It is a sensor which varies its resistance according to the temperature and is used to reduce the boiler power output to avoid damage to the plastic parts of the flue.

Tony

 

[Andrew Gower]

Well Andrew we are not permitted to give advice on gas or combustion aspects to DIYers. You should not have even opened the boiler casing as its a room sealed unit.

I don't see why you were looking at the flue sensor. F28 seems to relate to the water pressure switch!

Usually just needs water pressure topping up but on a dirty system the switch entry can get blocked with sludge.

The flue sensor is not a switch. It is a sensor which varies its resistance according to the temperature and is used to reduce the boiler power output to avoid damage to the plastic parts of the flue.

Tony

Thanks, the reason I said about the flue sensor is that there was an old thread on here from 2010 with the same error code and replacing the sensor sorted his problem. As a new sensor did not sort mine that is why i was wondering if the new sensor was faulty. Better get someone in I suppose.

 

[Agile]

What is your indicated boiler pressure?

Link to other 2010 thread?

Tony

 

[Andrew Gower]

Approx 1.25 bar

//www.diynot.com/diy/threads/ravenheat-he120t-low-nox-error-code-28-problem.237589/

 

[Agile]

That other thread describes a flue fusible link and not a flue temperature sensor.

The link seems to be wired in series with the water pressure switch to turn off the boiler if the flue is dangerously hot.

It appears the link is not mentioned in the manual. Possibly as an oversight, but most likely intentionally as it is a safety device which only a gas reg engineer should be touching.

Ravenheat are very keen to protect the public from unqualified tamperers and since any RGI can call them and hear about it then they may feel it is justified to do that.

Tony