Suggestion for best website to provide Boilers
 

Hi all. One of our members has informed me that they have been asked to make a payment (50%) to a business before installation of a new boiler. Is this something you would ask for or should they be wary of paying before any work has been started/completed?
Can any one suggest me a website to provide Boilers.
I have also searched http://www.boilerquote.net/boilers/boiler-types.php website. but I don't know this website boilers service. so can you please review this website after that I will be calling them.
Thank You