Have a look in your local paper - there are a number of engineers who give free estimates in mine.
As you rightly recognise, an estimate is little more than a ball-park figure, and not a quotation to put the boiler back in working order, but some people take an estimate to be the latter.
If someone is going to call, and assess the problem, and put an estimate in writing, and come back again, it's invariably going to add to the cost of the repair.
BG say they do fixed price quotes, but in my experience BG usually charge twice the average rate anyway, so 'knowing where you stand' comes at a price, but I suppose the pain is up front.
Generally, consumers are advised to get more than one estimate for a job, but life is often not as simple as it seems when someone is being wise after the event, i.e. those who tell someone who has been ripped off that they should have got a price before having the work done.
There are pros and cons on both sides, but how they get handled will vary from one tradesman to another, so keep looking and keep asking until you find someone you feel comfortable dealing with.
A rational reply, but sure other would agree as you state it is good to get to two estimates this would be difficult others have posted they don't giving estimates?
Yes i have company who were polite on the phone answered my questions and assured me that a quote would be giving after initial diagnoses.
For those who think i just being awkward i will give you a run down of my fiancée experience before i met her.
She a teacher and teacher trainer so know how to deal with people.
Age 28 she brought her flat which need central heating installing.
The company who did the installation never completed job leaving pipes exposed and damaged created when running in pipe un-repaired. The fobbed her off and never returned her calls.
When the boiler need repairing a few years later the company she got did mis diagnosed it, did repair it and over charged her. She had to face abusive calls from them, but eventual won her court case.
Her toilet broke and required new cistern, the first plumber told her go to local plumbing shop and get the parts, at the shop felt uncomfortable asking for a part that contained the words 'ball cock' this was not easier by the guys in the shop smirking and treating her like an idiot.
The plumber fitted part, but it kept leaking into the bowl and her good fix this and eventual just stop taking her call. A second plumber was called out he too could not fix it.
When i met her it was the first thing i fixed, the problem was it had not been fitted correctly so the seal was flush and so leaked.
After this she stopped getting work done on flat as she did not want to deal with tradesmen, she tell me all her work colleges have had similar experiences. This is why people are cautious.