Vaillant Ecotec 428 boiler really inefficient. Any tips?

[harrysmith123]

Had a vaillant ecotec plus 428 installed in November 2010 into existing sealed microbore system (10 years old). System not flushed but anti sludge treatment added.

Just got the bill for last 3 months of gas use and, bearng in mind that the heating hasn't been used much due to mild weather, we've used significantly more gas than for the same period in previous years. We've double checked these figures and they are actual readings - not estimated.

Before this boiler, we had an awful Potterton 120L, which kept breaking down. The research suggested this Vaillant 428 boiler should be very efficient so we're really surprised to see how much more gas it's using than the Potterton and the house is no warmer.

Anyone had the same problem? Or have any ideas/tips on what could be wrong?

 

[45yearsagasman]

System not flushed but anti sludge treatment added.

That can't be correct for starters. A system should be cleaned correctly before fitting a new boiler for the system to be efficient.

 

[Agile]

Its not usually possible to simply compare bills.

Weather varies and the price of gas has doubled over a few years.

That boiler cannot lose heat. You must be using it!

Tony

 

[harrysmith123]

Just to clarify - it's the actual gas usage which has risen (in Kilowatt hours), not cost.

This winter, we have hardly had the boiler running at all during the day as the weather has been so mild so we were expecting low usage. We've also installed a log burner this winter so we were keeping main central heating thermostat relatively low in evening.

a) Usage is worse now (Nov., Dec. 2011 and Jan. 2012) than for comparable period immediately after Vaillant boiler installed (Dec. 2010, Jan., Feb. 2011) - so it is now less efiicient than when first installed. Last winter was cold here and heating was run during the day.

b) Usage is worse since new boiler installed than for comparable periods in previous years when we had the old boiler.

Does anyone know if a power flush or balancing the radiators would help?