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Maintenance and Service

Exam revision materials for Plumbing Level 2&3 and ACS Gas Safety test

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Boiler Overheat Lockout




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Ideal Elan RS30






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Vokera Sabre 25HE





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Crosswater SME-029


Grohe Sentosa


Hudson Reed

IB Thermostatic Shower



Sirrus Rothwell R995 Antique Shower




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Geberit AP109


Gas Safety Inspection

Gas Flue Analysers

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ecoTec plus 824 boiler - F.20 fault code

Vaillant ecoTec plus 824 boiler displaying F.20 code. No heating or hot water

  • The boiler overheats due to a poor water circulation or a faulty NTC flow temperature sensor
  • Replacement part number is Vaillant NTC Sensor 193592
< Go Back2014-03-08

ecoTec old boilers - Vaillant Gasket Seal 0020038679

Vaillant ecoTec old boilers every 5 years require a burner gasket replacement

  • replace the burner gasket every time the burner lid removed for a boiler maintenance or service
  • the replacement part number is Vaillant Gasket Seal 0020038679
  • this part number suitable for the whole ecoTec range including ecoTec Plus 937
< Go Back2014-03-08

ecoTec plus 824 boiler - fault F.75 (no heating and hot water)

Vaillant ecoTec plus 824 boiler - fault F.75 and the boiler doesn't fire up

  • the boiler can't detect a pressure rise when the pump is on
  • recharge the expansion vessel with a bicycle pump
  • replace the water pressure sensor or clean the existing one
  • the part number is Vaillant Water Pressure Sensor 0020059717
< Go Back2014-01-12

Thermocompact VC GB 242 EH - gas valve fault

Vaillant Thermocompact VC GB 242 EH gas valve is letting by when the boiler is off.

  • the gas valve is faulty it doesn't fully close
  • need to replace the whole part only
  • the gas valve replacement part is 053255
< Go Back2014-01-02

ecoTec plus 637 - PCB replacement

Vaillant ecoTec plus 637 doesn't show any signs of live. The incoming voltage is ok but LCD is off.

  • It is a main PCB or a screen PCB has gone down
  • To test wich one measure DC voltage between earth and one of the wires of X20 in the top left corner (red plug). 
  • If there is 5v DC then the screen PCB is faulty
  • If there isn't any voltage then replace the main PCB
< Go Back2013-11-23

ecoTec plus - pump replacement

Vaillant ecoTec plus 831 boiler was making a loud noise when operating.

  • The pump was making the noise
  • The pump started to leak in few days
  • Pump replacement part number is 178983
< Go Back2013-10-18

combiCompact VCW - No heating but hot water is working

Vaillant combiCompact VCW - Hot water is working, on heating demand the pump is running but no ignition occuring.

  • Make sure that the diverter valve micro-switches are making the circuit, both of them. You can see it once turn the heating on. The spindle will push 2 bittons inwards. 
  • If this is not happening then you can adjust two screws so they press the buttons
  • Also remember that this boiler has a heating delay set by manufacturer on 5min. It means that after turning the heating off it will only come on again minimum after 5 minutes.
  • You can adjust it on the front panel.
< Go Back2013-10-17

ecoTec pro 24 - error code F.75

I have Vaillant ecoTec pro 24 combination boiler which have stopped working and displaying error code F.75

  • Check the pump first. Reset the boiler and check voltage between blue and brown to the pump. If it showes 240V intermittently avery 5 seconds and you can hear an intermittent buzzing noice from the pump then the pump need replacement
  • The part for replacement is: Vaillant 178983 Ecotec Pro Plus PUMP ORIGINAL
< Go Back2013-08-15

TURBOmax Plus 824E - broken filling valve

Vaillant TURBOmax Plus 824E - broken filling valve. If the built in filling valve is broken or impossible to open then you have 2 options whether to replace the built in valve or to fit an external one. To replace the built in valve isolate the boiler on flow and return pipes and drain it down replace both valve on a cold water side and the central heating side, open the boiler and refill the system up to 1.2 bar. To fit the external filling loop drain the whole central heating system ad tee off from both the central heating return and cold water pipe to 15mm copper and fit the filling loop so the double check valve is on the central heating pipe side. Refill the system. For the built in filling valve see details below:

The part number is 014675 and you can order it from here.

Vaillant TURBOmax Plus 824E manual: PDF

< Go Back2013-04-03

TURBOmax Plus 824E - no heating, no hot water

Vaillant TURBOmax Plus 824E - no heating, no hot water, boiler is not firing up. Start the boiler and if the fan has gone you will hear buzzing noise. Open a front cover and remove a combustion chamber cover. Start the boiler again and watch the fan impeller. If you can see it has stacked then try to lubricate it and give it a spin. The fan should start spinning and the boiler will fire up. If the fan makes a strange noise at all then it will likely to stuck again very soon and you need to consider the part replacement. Measure the CO/CO2 ratio and if it is not more than 0.004 then you can leave it as a temporary fix until the part replacement.

The part number is 190215 and you can order it from here.

Vaillant TURBOmax Plus 824E manual: PDF

< Go Back2013-03-30