I fit new gas boilers across Gateshead, from Low Fell to Whickham and out towards Blaydon. One fixed price, one day for most combi swaps.
Gas supply size, flue route, mains water flow rate, radiator condition and where the condensate can run to. Those five things decide whether a job is straightforward or not, and none of them can be assessed over the phone.
You get one written price covering boiler, parts, labour, flush, filter and removal of the old unit.
The terraces around Felling and Dunston often still have gravity fed systems and cylinders in an airing cupboard. Converting to a combi frees up that space, but only if the mains flow supports it, so that gets measured before anything is promised.
Every job is different, so these are guide figures rather than a quote. You always get one fixed written price after I have seen the work.
Tell me what you need and I will come and look at it. You get the price before I start.