Learn what you can do to help your systems run smoothly and reliably! Note: your review may be shared publicly. Makes removing stains and odor simple! There is no such thing as the best combi boiler, however there is the best combi boiler for the job with that in mind we've taken a look at some of the most popular high quality combi boilers that we sell. Mike and i are still in love with our bathrooms — and would recommend avon plumbing without hesitation! Oxapanone homoplymer,.