Huge range of fees - how to decide?

Use this site if you have not already to choose suitable qualified tradesmen, you can see there customer reviews then you can make a more informed decision but make sure they are qualified to undertake the work in hand and can prove it, so don't be shy asking for such proof as not only is it a legal requirement but also will affect the un-vented cylinder warranty if they are not! The tradesmen that you have selected to quote, their prices should be in the same ball park and last ask if they guarantee their work and trust your own good judgement or intuition as to whether you can rely on this person to A. Be competitive and B. Takes pride in their work. Good luck

Cheap guys are normally the ones struggling for work - and there's always a reason, good tradesman aren't quiet tradesman, over the top expensive guys more often than not dont want the work. they are quoting high so that if they win it atleast they are making good money for something they dont want to do dont go for most expensive quote, dont go for cheapest. there will always be a middle ground