Help please on No dhw on Keston C36 Combi

[PlumbSafe]

I have a breakdown, Keston c36 with no hot water, it was not circulating from pump hydroblock to the plate heat exchanger, so I fitted a new 3 3 way valve, still not moving over to hot water, replaced dhw thermister, still no hot water, the flow switch is working and the boiler is starting up, but won't send it round the dhw heat exchanger. Any thoughts lads. Cheers

 

[PlumbSafe]

I was told by another engineer on the CC that it could be the Capacitor to the 3 way valve. any other thoughts, could it be the control box board or the DHW Thermistor.

 

[Billy Bob Bob]

could have a blocked plate heat

 

[PlumbSafe]

no the HEX is clear as I can manually divert the flow in to it once I take the 3 way motor out and push the diverter arm with my finger, the 3 way valve does not move out on DHW, it stays in keeping it on HTG, On DHW it operates the flow switch and even ignites the boiler, it just does not divert to the Plate HEX, I am thinking its either the Control Box PCB or the in-line Capacitor as there is power to the 3 way valve moter, it has 2mm of movement but not enough to push the arm to the DHW. any other Ideas

 

[aggis]

If you can get hold of the capacitor reasonly quickly I'd try that 1st.

 

[PlumbSafe]

it was the capacitor, part c36 combi r-c assembly c.10c.4.20.00.0 (the red one)

 

[Reg Man]

Agree with Aggis Capacitor issue.

 

[SafeGasInstall]

could any one give brief explain what does capacitor do ???

 

[Reg Man]

A capacitor is a passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). When there is a potential difference (voltage) across the conductors, a static electric field develops in the dielectric that stores energy and produces a mechanical force between the conductors. An ideal capacitor is characterized by a single constant value, capacitance, measured in farads. This is the ratio of the electric charge on each conductor to the potential difference between them.
Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass, in filter networks, for smoothing the output of power supplies, in the resonant circuits that tune radios to particular frequencies and for many other purposes.
The effect is greatest when there is a narrow separation between large areas of conductor, hence capacitor conductors are often called "plates", referring to an early means of construction. In practice the dielectric between the plates passes a small amount of leakage current and also has an electric field strength limit, resulting in a breakdown voltage, while the conductors and leads introduce an undesired inductance and resistance.

 

[SafeGasInstall]

very professional technical description of capacitor ! thank you Reg Man !you obviously now your staff.In another words what is his job in the boiler! and why has he fail in this occasion ???

 

[Reg Man]

Its amazing what you can find out on the internet (LOL), did you understand it? I struggled, so must not take credit. I think its all about making sure a smooth delivery of power. This is quite a common fault on the C36.

 

[SafeGasInstall]

I thought you have a degree in electronics !)))

 

[fuzzy]

doesnt it help motors start?