Why didn't this thread exist like three months ago, haha
I had central heating installed and it took the plumber three days total, that also on a 3 bed / 1 bath house.
But yeah, deffo shop around, first quote I got was the highest at £5500, and that was using an Alpha combi, 7 radiators, wireless control unit and labour for a week.
My brother and I did some research and went to local plumbing supply centre and asked about Alpha and the salesman said that they weren't the best.
We then asked plumbers that randomly walked into the shop and the general consencus was that "Alpha? They're cr@p mate".
After getting three more quotes, we finally found a decent local plumber that did the job in three days and a Vaillant was used, job cost £4000 in total.