Alpha and worcester were recommended as the most reliable by various plumbers I spoke to.
I went for an alpha in the end, there was an intermittent fault with it immediately upon install which appears to be bad luck. It worked but req.regular resets (4/5 times a week during the winter). None of the engineers had ever heard of the fault and Alpha sent 3 before their senior regional engineer replaced a 4" peice of wire which had been damaged. Since then it has been no problem.
The service dept is polite efficient and quick and I can't fault them at all.
It is difficult to compare it's efficiency with the prev. combi boiler boiler as we had an extension, 3 extra rads and our daytime use increased however I use £20 pcm gas for a large 3 bed semi. The hse isn't over heated (thermostats set to 21 deg and the htg is on 10 hrs per day.
The boiler itself fills a bath pretty quick and heats up the rads in about a minute from cold.
we have a glowworm 30cxi and it works well but has had 3 callouts in 2 years for the same fault mains water inlet seal leaking. (nylon nuts and seals). seems its blamed on high water pressure!.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.