One-Off Boiler Service Cost vs a Monthly Care Plan (UK 2026)

“Just pay for the service, or go on a plan?” is a question homeowners ask every autumn, and it’s one heating engineers building their own recurring offer need a straight answer to as well. Here’s what a one-off service costs against what a monthly plan actually adds up to over a year, sourced from provider pricing rather than a rule of thumb.

A service and a gas safety check aren’t the same job

Two different jobs get lumped under “boiler service.” A landlord’s gas safety check (the CP12) covers every gas appliance in a property, not just the boiler, and typically costs £60 to £90 for a boiler plus one other appliance, rising to £80-£120 for a boiler, hob and gas fire together, with London and the South East running 15-30% above that [4]. A boiler service is narrower: the manufacturer-recommended annual check on the boiler itself, and it’s priced differently again.

What a one-off boiler service costs right now

A standard gas combi boiler service runs £80 to £120, averaging £100 to £110 across the UK [3]. HomeServe’s own guidance puts the average a little higher, at £100 to £130 [2]. System boilers cost slightly more, £90-£130 (average £110), and oil boilers more again, £95-£145 (average £120) [3]. That single visit buys one thing: a Gas Safe engineer confirming the boiler is safe and running efficiently [3]. It doesn’t cover what happens if a part fails the following month.

What a monthly plan costs — and what kind of plan it is

Not every “monthly” boiler product is the same product. Some spread the cost of the service alone across the year with no breakdown promise attached: HomeServe’s own service plan prices a boiler service at £60 for the year, or £5 a month [2] — at or below the £80-£120 one-off price for a comparable job [3]. Full cover/care plans are different and cost more: boiler-only cover typically runs £8 to £13 a month outside London and the South East (£9-£15 within them), stepping up to £12-£17 a month for boiler-plus-heating cover, and £18-£25 a month for full cover including plumbing, drains and electrics, each tier running roughly 10-20% higher again in London and the South East [5]. British Gas’s own entry-level HomeCare Basic plan is currently £16.50 a month, discounted from a full price of £22.00 a month, with a £60 excess and an annual boiler service built in [1].

Product	Typical cost	Rough annual total	Breakdown cover included
One-off service [3]	£80-£120 per visit	£80-£120	No
HomeServe service plan [2]	£5/mo	£60	No
Boiler-only cover [5]	£8-£13/mo	£96-£156	Yes
British Gas HomeCare Basic [1]	£16.50/mo (promo), £22.00/mo full	£198-£264	Yes
Full cover (heating, plumbing, drains, electrics) [5]	£18-£25/mo	£216-£300	Yes

Running the maths over a year

Line the numbers up and two different comparisons are happening at once. Against a pure service-only monthly plan, paying monthly barely changes anything: HomeServe’s £60-a-year service plan [2] sits inside the same £80-£120 range as paying for one visit outright [3] — the customer is just smoothing cash flow, not buying anything extra. Against a genuine cover plan, the gap is real: the cheapest boiler-only cover adds up to roughly £96-£156 a year [5], and British Gas’s own entry plan comes to £198-£264 a year once the current 25% promotional discount is accounted for [1] — both well above a single £80-£120 service [3]. Full cover with plumbing, drains and electrics reaches £216-£300 a year outside London, more again within it [5].

What the extra money on a cover plan actually buys

The gap between a one-off service and a cover plan isn’t padding — it’s parts and labour for boiler breakdowns, engineer call-outs beyond the service visit itself, and on the higher tiers, cover for central heating, plumbing, drains and electrics too [5]. British Gas’s plan also lets a customer choose their excess, with £60 the default and £0 or £99 options available, trading a lower monthly price for a bigger bill if something does go wrong [1]. None of that exists on a one-off service or on a pure service-only plan like HomeServe’s £5-a-month product [2] — both cover the check-up and nothing else.

Which is worth it — for a homeowner, and for an engineer pricing a plan

For a homeowner, the logic runs in reverse of what a lot of plan marketing implies. On a young boiler still under manufacturer warranty, a one-off annual service at £80-£130 [2][3] is usually the cheaper, sufficient choice, because there’s little yet for breakdown cover to protect against. Once a boiler is old enough that a repair would land squarely on the customer, the extra £96-£300-plus a cover plan costs over the year [1][5] is buying certainty, not just a check-up.

For a heating engineer pricing a recurring offer, the market shows two workable, honestly different products sitting side by side. A service-only plan priced like HomeServe’s, around £5 a month [2], is a payment-smoothing product — fine to sell, as long as it isn’t dressed up as breakdown cover. Genuine cover, priced like British Gas’s or the wider market’s £8-£25-a-month range [1][5], is a different sell entirely, and needs to be priced against what callouts and repair parts actually cost in the business, not against a competitor’s promotional headline rate. Being clear with a customer about which of the two they’re actually buying is what keeps a plan renewing instead of getting cancelled the first time a customer discovers what it doesn’t cover.

What to do next

If you’re weighing up whether to launch your own monthly plan against simply charging for one-off services, get someone outside the business to check your price against what these providers are already charging before it goes in front of a customer. Loomwork Ai runs a short paid review for trades building a recurring-revenue plan offer.