Vaillant ecotec plus 438 no heating or hot water

[noddy997]

thermistor needs replacing. I'd take any bets on that being the fault

Where's this located?

Would this still be the issue even when heating and water are cold and have not been on for hours?

 

[noddy997]

The orange wire from the motorised valve ( in the 5th terminal, from the right hand side) Is what sends voltage to the boiler via that terminal. So ,when only c/ heating is called for That orange wire should have 230/240 volts ,measuring between it and earth.

Problem is back.

I've honestly had enough with it!

 

[BlueLoo]

Problem is back.

I've honestly had enough with it!

My suggestion is to start from scratch tbh.
Power flushes, new pumps, new 3 way valves etc. What you had is no longer what you have.
Your wiring is terrible.
You pumps are set possibly incorrectly.
The boiler is maybe faulty.

I'd be drawing the system out carefully, then, do a wiring schematic to suit, then, review both for what is and what should be (ie, the pump is wrong) and then set out from there.
I'd rewire, or at least, reconnect, the wiring stuff.
Don't forget the controllers and thermostats in the schematics..

 

[noddy997]

My suggestion is to start from scratch tbh.
Power flushes, new pumps, new 3 way valves etc. What you had is no longer what you have.
Your wiring is terrible.
You pumps are set possibly incorrectly.
The boiler is maybe faulty.

I'd be drawing the system out carefully, then, do a wiring schematic to suit, then, review both for what is and what should be (ie, the pump is wrong) and then set out from there.
I'd rewire, or at least, reconnect, the wiring stuff.
Don't forget the controllers and thermostats in the schematics..

Thanks but the wiring remains the same for 24 years.

I fitted a new valve yesterday and a new pump today and whilst the heating has worked its doing the old trick again.

Voltage is being received at the 3 port valve and pump is not kicking in despite receiving the voltage. It is a new pump fitted today.

Unless the flex cable is playing up at the pump?

 

[terryplumb]

Is the boiler firing up ?

 

[BlueLoo]

Thanks but the wiring remains the same for 24 years.

I fitted a new valve yesterday and a new pump today and whilst the heating has worked its doing the old trick again.

Voltage is being received at the 3 port valve and pump is not kicking in despite receiving the voltage. It is a new pump fitted today.

Unless the flex cable is playing up at the pump?

Exactly.
Go tighten a few of the screws. They can work loose over time due to electro-thermo somethingorother.

 

[noddy997]

Is the boiler firing up ?

Nope. No fault codes either

 

[noddy997]

Exactly.
Go tighten a few of the screws. They can work loose over time due to electro-thermo somethingorother.

I did yesterday

 

[BlueLoo]

Thanks but the wiring remains the same for 24 years.

I fitted a new valve yesterday and a new pump today and whilst the heating has worked its doing the old trick again.

Voltage is being received at the 3 port valve and pump is not kicking in despite receiving the voltage. It is a new pump fitted today.

Unless the flex cable is playing up at the pump?

The pump recieving the voltage?

The boiler controls (powers) the pump, no?

You have wired the pump to the boiler yea?

 

[noddy997]

The pump recieving the voltage?

The boiler controls (powers) the pump, no?

You have wired the pump to the boiler yea?

All wired exactly the same.

Problem with the block connectors is you can't test an individual wire you do it by the screws and there's multiple wires sometimes in one connection.

The pump live and earth are receiving power as from what i can tell

 

[BlueLoo]

Pics?

 

[terryplumb]

You are going around in circles. As already advised you must measure voltages present at different points in the wiring centre , with the controls set at various settings, to establish what isn't functioning as it should.

 

[noddy997]

You are going around in circles. As already advised you must measure voltages present at different points in the wiring centre , with the controls set at various settings, to establish what isn't functioning as it should.

Sorry but am unsure on how to measure.

Orange to earth green gets 240v

Pump live to orange gets 240v

Thats with heating on and thermostat on high


Can you please advise on what else and how to measure?

 

[BlueLoo]

At the grey and orange wire terminals at the valve (for the cylinder stat) was getting 170v rather than 240v. This was when the water was off.

The green cable from the valve to the white cable was getting 240v when heating was on.

Heating was set to permanent on.

Siemens RWB9 programmer and salus rt310 stat.

Eh?

Green is clearly earth here?

 

[noddy997]

Eh?

Green is clearly earth here?

Refer to terrys post yesterday at 615