You'll probably save money if you pay for services and repairs as you go along, rather than take out a boiler servicing contract - where you pay a monthly fee that also covers repairs our analysis shows that for more than nine out of ten which? members this was more expensive than paying for one-offs which? members pay an average of £72 for a one-off boiler service. Shows which top cards you're most likely to get. This drainbo stain and odor eliminator tackles.