New Alpha CB28 micro switch

[Ian Glass]

Hi all,

I am rather perplexed with a micro switch issue I currently have and was hoping you could kindly provide an explanation as I am baffled...

My current alpha boiler started playing up recently by only providing hot water when the CH was on then it started only providing hot was now and then.

After a visit form a local engineer he informed me the microswitch was stuck, he did free it and we had HW for a few days until the problem rerurned.

Today I bought a replacement switch from euroboilers, however the strange thing is once I replaced it the new switch is working the wrong way... that is to say, the boiler runs with no demand for HW or CH and when the hot water tap is opened the boiler switches off??

Common sense would tell me it is the wrong way round, however the electrical jack plug is two different shapes so it can only be connected one way??

I found this really strange, so I reconnected the old switch was was still working intermittently and found the boiler runs as normal and when I press the micro switch the boiler stops.

However the new one does the opposite i.e the boiler does not run unless I press the switch ??

I guess this is really a very stupid mistake I have somehow made or a faulty new switch which has been wired wrong...

And advice would be most welcome on this issue for my own sanity

 

[thereisawizza]

Are you Gas Safe Registered?

 

[bazdaman]

Wrong switch i suspect a different problem though

 

[Agile]

Be aware that many of those cheap parts suppliers are not supplying original maker's parts but copies.

Apparently not a very good copy in your case.

I don't remember exactly how the switch is connected in your case. It might be possible for you to correct the connections yourself.

Tony

 

[DP]

The microswitch when released or off the diverter, will fire the boiler for hot water. Primary flow will go to radiators though if switch not in the pocket on the diverter valve

I do not think you have a switch problem. Run central heating and see if you get hot water every time while CH demand active

 

[Agile]

Primary flow will go to radiators though if switch not in the pocket on the diverter valve

Actually not so!

The flow will go to wherever the diverter valve sends it according to which position it is in.

The switch only turns on the boiler.

 

[DP]

Actually not so!

The flow will go to wherever the diverter valve sends it according to which position it is in.

The switch only turns on the boiler.

Tony, look at the thread title. If I am not mistaken, boiler is a CB28. With no HW demand, diverter will always be in CH mode, so withdrawing the horseshoe switch fires the boiler and primary flow always to radiators.

Perhaps you need to look at the boiler and type of diverter utilised there. There is no way the diverter will be bi positioning

 

[Agile]

This is a conventional diverter although slightly different to most others.

Consequently the diverted position will depend on the DHW flow regardless of the switch being in position or not.

 

[DP]

Tony read carefully what I wrote
If the switch is removed, boiler fires and primary flow to radiators. Where did I say hot tap is running? So why should the diverter be in any other position but for flow to CH port?

If the diaphragm has a rip in it, that diverter will not move to any other position, it will stay in CH mode when hot tap run

 

[ianmcd]

This is a conventional diverter although slightly different to most others.

Consequently the diverted position will depend on the DHW flow regardless of the switch being in position or not.

Tony not unusual for you to get things completely wrong , the horse shoe switch on this boiler is powered when it is removed so the boiler senses a DHW demand but the diverter valve is still in the CH position, admittedly that unless you are experienced in this boiler like DP is then you will find it hard to work out, that is why so many of these switches were sold to so called engineers that dont know how they work

 

[ianmcd]

Tony read carefully what I wrote
If the switch is removed, boiler fires and primary flow to radiators. Where did I say hot tap is running? So why should the diverter be in any other position but for flow to CH port?

If the diaphragm has a rip in it, that diverter will not move to any other position, it will stay in CH mode when hot tap run

some people just dont know when to shut up Dan

 

[Agile]

None of you seem to be able to understand the simple English language.

If the switch is removed then the boiler fires up because it has been placed in a hot water demand condition.

Where the system water goes however depends on the position of the diverter valve.

That is determined solely by the diaphragm unit and can be either CH or DHW

 

[45yearsagasman]

Tony you don't understand English either, or in fact the way this boiler works. The situation being discussed is that when the switch is removed the boiler will fire but send water to ch circuit. This will happen as a default. If the hot water tap is opened then the diverter will move and send water to the plate. No one has mentioned opening said hot water tap as I see it.

 

[DP]

Bernardgreen.
This if for your benefit
Boiler in question has a diverter which in rest position has CH port open
A switch fitted to this diverter is operated by a shaft while the diverter is in said rest position. The switch in this operated mode is in the OFF state
If the switch is removed, the plunger releases telling the boiler to start up.
Heated water passes to radiators.
The diverter cannot be in any other position but the positioned to deliver water to ch port

Can you share your thoughts as to how primary water would go to HW port as well as Tony suggests?

 

[Agile]

My replies have covered all possibilities of the boiler operation.

Of course I understand the operation of the boiler.

Unfortunately my personality and upbringing is not to be abusive to anyone!

Tony