Intergas...but which...

[bernardgreen]

Bernard, under what circumstances do you envisage this catastrophic event?

If the DHW flow sensor gave a false Flow indication.

Shall we throw in the water meter having a non return valve in it?

Not a good idea as the boiling and expanding water would have nowhere to go. Pressure would increase. and the DHW circuit has no way to relieve it. ( or are there pressure relief valve on the DHW circuit as well as on the CH circuit.

And this bonding.... What bonding are you referring to?

The bonding between aliminium block and copper tube across which heat has to be transferred if the water is to be heated.

Heat sinks for electronic components often use conductive paste between copper and aluminium in order to maintain thermal conductivity when differential expansion of the two dissimilar metals affects the mechanical interface between them.

 

[Dan Robinson]

DHW flow sensor gave a false Flow indication.

Flashing 11 error. Hardly catastrophic.

Not a good idea as the boiling and expanding water would have nowhere to go

Newsflash. They've had them for years.

The bonding between aliminium block and copper tube across which heat has to be transferred if the water is to be heated

And the binding used in the Intergas is......?

 

[Dan Robinson]

the DHW flow sensor gave a false Flow indication.

And how does the current flow sensor used fail to on?

 

[bernardgreen]

Flashing 11 error. Hardly catastrophic.

It only flashes 11 if the processor in the control system is aware that the sensor is saying there is flow and something else ( probably overheat sensor ) tells the control system the heat from the flame si not being taken away from the boiler by water.

Newsflash. They've had them for years.

Had what, try writing details into your posts.

And the binding used in the Intergas is......?

Looking at the video you posted on YouTube it appears that the "binding" is only mechanical pressure as the hot liquid aluminium cools and shrinks around the copper tubes.

 

[bernardgreen]

And how does the current flow sensor used fail to on?

As I do not know what is used for the switching element in the sensor and whether it closed or open when water is flowing I cannot answer that question in relation to the sensor.

If it is closed when water is flowing then a short in the loom could false indicate flow. If it is open when water is flowing then a snapped wire or dislodged connection would false indicate flow.

Maybe it is a pulse output turbine sensor. Only if there is a pulse sequence should the control system recognise it as flow. That is however an expensive solution.

 

[Corgigrouch GTi]

It only flashes 11 if the processor in the control system is aware that the sensor is saying there is flow and something else ( probably overheat sensor ) tells the control system the heat from the flame si not being taken away from the boiler by water.



Had what, try writing details into your posts.

Looking at the video you posted on YouTube it appears that the "binding" is only mechanical pressure as the hot liquid aluminium cools and shrinks around the copper tubes.

You have answered your own question.. If the processor does not get the message that there is flow, then the boiler will not fire for DHW, if the processor does (By some fluke) get that message falsely, fires the boiler, then there will be an overheat code and will lock out..

Water meters, to the best of my knowledge have non return valves in them... Worcester used to say that their kit should be fitted with a shock arrestor to prevent damage to the plastic hydroblock.. Only ever seen one fitted.



Mechanical pressure is the force that holds almost everything together, so it is a well proven technology..

 

[Corgigrouch GTi]

Maybe it is a pulse output turbine sensor. Only if there is a pulse sequence should the control system recognise it as flow. That is however an expensive solution.

That'll be why boilers are so expensive..

 

[bernardgreen]

Mechanical pressure is the force that holds almost everything together, so it is a well proven technology..

And differential expansion of dis-similar materials can adversely affect that pressure. That is why springs are used to maintain the pressure when the materials that have to be held together are those that can suffer plastic deformation when under pressure. ( checking that electrical connections in terminal blocks are still tightly screwed )

 

[Corgigrouch GTi]

And differential expansion of dis-similar materials can adversely affect that pressure. That is why springs are used to maintain the pressure when the materials that have to be held together are those that can suffer plastic deformation when under pressure. ( checking that electrical connections in terminal blocks are still tightly screwed )

Perhaps you could advise Intergas where they are going wrong and why they have such a high failure rate of their HEXs.. I forget how many have failed to date.. I hear what you say about having to tighten screw terminals, that is why the trend is towards spring loaded connectors such as those from Wago

 

[Dan Robinson]

Had what, try writing details into your posts.

Non return valves in water meters. I'm replying to your statement for God's sake.

As I do not know what is used for the switching element in the sensor and whether it closed or open when water is flowing I cannot answer that question in relation to the sensor

For the forum googleer in chief and self professed expert in control systems, your aught to be able to work it out.

It only flashes 11 if the processor in the control system is aware that the sensor is saying there is flow and something else ( probably overheat sensor ) tells the control system the heat from the flame si not being taken away from the boiler by water.

Flashing 11 is the overheat error code.

But then reading the manual would have told you that.

And how does the current flow sensor used fail to on?

A clue...... It can't.

 

[bernardgreen]

your aught to be able to work it out.

I would have to have a sensor in my hand to work out how it worked.

Simple micro switch, or doppler velocity measurement. or somewhere in between

A clue...... It can't

Of course it can fail into a false state. Most unlikely but it can happen, cost versus probabilty and consequential loss due to a failed sensor results in a single sensor being trusted.

 

[Dan Robinson]

Of course it can fail into a false state

How can it fail to on?

 

[bernardgreen]

Flow Sensor 844797

Three wire lead so quite possible an active sensor and not just a micro switch.
T shaped so quite possibly a paddle in the flow,
Unlikely to be an opto sensor with the paddle arm breaking a beam.
Possibly a Hall Effect sensor detecting a magnet field affected by the paddle arm.

If the sensor is active then the output from the sensor will have to be switched by a semi-conductor device and that device might go open circuit or short circuit.

 

[Razor900]

Perhaps you could advise Intergas where they are going wrong and why they have such a high failure rate of their HEXs.. I forget how many have failed to date..

That's an easy one.

Almost 3 million made and so far mechanical failures equal none.

Or 0.0% if you prefer

 

[Corgigrouch GTi]

That's an easy one.

Almost 3 million made and so far mechanical failures equal none.

Or 0.0% if you prefer

That's what I thought but I just thought that our resident Google King might have found one....