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Andrew Smith
Andrew Smith, Engineer
Category: UK Plumbing
Satisfied Customers: 3381
Experience:  Domestic Gas, Commercial Gas, LPG, Unvented Hot Water, Part P Electrical, Commercial Catering
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Hi, My vaillant ecotech pro 28 has fault code s30 on it.

Customer Question

My vaillant ecotech pro 28 has fault code s30 on it. ? no demand for heating but all thermostats on the rads are full on as I want to test system. When I press both the - and plus buttons at the same time the heating comes on for about 5 minutes then goes off. ( A BGas engineer did this last year for servicing or something) any ideas why my heating won't stay on.
Submitted: 3 years ago.
Category: UK Plumbing
Expert:  Andrew Smith replied 3 years ago.
Hi my name is Andrew - lets see if we can get you sorted in the shortest possible time. Do you have a room thermostat, as this will have overall control of your heating?
Customer: replied 3 years ago.

I did have. but as we also have underfloor heating in the main living area it was not effective so I was advised to disconnect it. (we only want it on on it's lowest setting to take the chill off the floor, and to leave on permanently through the winter ) The rad's in other rooms all have thermostats and the uderfloor heating has it's own temp. gauge or regulator.

Hope this makes sense.

Expert:  Andrew Smith replied 3 years ago.
Really you should have a 2 port motorised valve on the underfloor and one on the rest of the heating, that way you can have 2 separate temperature settings in the two zones (building regs say that you must have an overall temp control to turn the heating off) S28 is the anti cycling mode and also to keep the hot water inside the boiler up to temperature. It does not sound like the boiler is being told to fire the heating.
Customer: replied 3 years ago.

Hi, House was rebuilt 2 years ago and underfloor heating installed to building regs. It has the valve etc. Do you suggest I re-connect the room thermostat in the part of the house that has underfloor heating? Also the info. on the boiler is code s.30. which the book tells me means no heating required from the external controls. Which i asume means thermostats on the rads. Should i put all rads up high and see what gives?

Should I swith the mains to boiler off so it can re-set self? any other suggestions? Thanks

Expert:  Andrew Smith replied 3 years ago.
The TRV's do not tell the boiler to fire, it will be the programmer and room thermostat that tell the boiler to fire as they the electrical controls.
Customer: replied 3 years ago.
By programmer do you mean the boiler itself? as I've put it on for heating all the time, or do i need to wire the room thermostat in for the area of the house for underfloor heating, although I don't see why this is neccessary as they are independent? Thanks
Expert:  Andrew Smith replied 3 years ago.
The timer tells the heating when to come on (whether it is on the wall or on the boiler). The room stat is there to turn all the heating off when the house has reached temperature - so it should go in the coldest part of the house (usually the hallway) and then once the cold area has warmed up the heating is then turned off until the temperature drops again. The room thermostat should be wired back in, but underfloor heating normally has a thermostat of its own?

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