The tool works through parts availability, the cost of the specific repair, the appliance’s condition, efficiency, repair history and what else the system needs – which together give a far better answer than age.
Why age is a poor guide
A twenty-year-old cast iron oil boiler that has been serviced properly every year may be mechanically sound and worth keeping. A ten-year-old appliance that has had three call-outs in two winters and whose parts are becoming difficult may not be.
The factors that actually determine the answer:
- Parts availability. An appliance you cannot get parts for is an appliance waiting to fail permanently, whatever its condition.
- The cost of this specific repair relative to replacement.
- What else is likely to need doing soon, which an engineer who has just opened it up can tell you.
- The condition of the major components – heat exchanger, combustion chamber, casing.
- Efficiency, and what the difference is costing you annually.
- Repair history. Three visits in two winters is renting reliability rather than owning it.
- What else the system needs anyway – if it needs cleaning, controls and radiator work regardless, replacement is the moment those get done.
- How long you intend to stay.
The questions the tool asks
| Question | Why it matters |
|---|---|
| What is it, and roughly how old? | Establishes the parts and support position |
| What has failed? | Some components are routine; some are terminal |
| What is the quoted repair? | The comparison figure |
| How many repairs in the last three years? | Pattern matters more than any single fault |
| Is it still under warranty? | Changes the arithmetic entirely |
| Has it been serviced annually? | Affects both condition and warranty status |
| What condition is the rest of the system in? | If it needs work anyway, bundle it |
| Are you staying in the property? | Payback horizon |
| Is the current appliance correctly sized? | A replacement is the chance to fix an oversized boiler |
| Would you change system type? | Combi to cylinder, or oil to something else, changes the whole question |
Ask the engineer: what else is likely to need doing in the next two years? Somebody who has just had the appliance open can usually tell you, and a repair that is the first of three is a different proposition from one that is genuinely isolated.
Things that point clearly at replacement
- Parts no longer available, or on long lead times.
- Heat exchanger failure on an older appliance, because it is usually the most expensive single part.
- Combustion chamber breakdown on an oil boiler where the lining is not a serviceable part.
- Corroded casing on an external boiler, letting weather into the burner and controls.
- A tank that is weeping, crazing deeply or deforming – there is no repair for a containment vessel.
- A cylinder that is leaking – same reasoning.
- Three or more failures in two winters.
- Substantially lower efficiency than a modern equivalent, where you are staying long enough for it to matter.
- A system needing cleaning, controls and radiator work anyway.
- An appliance that was always wrong – badly oversized, or the wrong type for the household.
Things that point clearly at repair
- A routine wearing component – a pump, a fan, a valve, a thermostat, a sensor.
- Still under warranty, where the fault is covered.
- A well-built appliance that has been serviced properly and has no other symptoms.
- Parts readily available.
- An isolated fault with an identifiable cause that has been addressed.
- A system that is otherwise in good order.
- You are moving soon, and a working appliance is what matters.
- The repair is a small fraction of replacement and the engineer expects nothing else imminently.
We recommend repair more often than replacement, because most faults are routine components on appliances with years left. An engineer who recommends replacement for every fault is telling you something about themselves rather than about your boiler.
What the tool will not do
It will not give you a figure. We do not publish prices and we are not going to produce a pound number from a form – see what things cost.
What it does is structure the decision so that when you talk to an engineer, you are asking the right questions and can assess the answers. That is more useful than a number, because the number depends entirely on which specific part has failed on which specific appliance.
The architecture for it is defined and it is not yet live. When it is, it will be free, require no email address, and store nothing. In the meantime the framework above is the same one we use on the phone, and you are welcome to work through it with us.
The honest conversation
What you should be able to expect from whoever you ask:
- What has actually failed, and why – not just which part is being replaced.
- What that repair costs, itemised.
- What else is likely in the next two years, based on what they have seen.
- Whether parts are available, and how long they take.
- An honest view of the appliance’s condition, including when that is good news.
- What a replacement would involve, including the things around it – system cleaning, controls, flue, condensate.
- No pressure. A decision this size should not be made on a doorstep.
Facing the decision? Ask what else is likely in the next two years. That single question settles most cases.
Questions we get asked about this
How old is too old for a boiler?
Age alone is a poor guide. Parts availability, condition, repair history and efficiency matter far more. Plenty of older appliances that have been serviced properly are worth keeping.
What is the rule of thumb for repair versus replace?
There is not a reliable one. The commonly quoted rules based on age or on repair cost as a percentage of replacement ignore parts availability and what else is imminent, which are usually the deciding factors.
Will you tell me if my boiler is worth keeping?
Yes, and it happens regularly. Most faults are routine components on appliances with years left, and an engineer who recommends replacement for every fault is telling you about themselves rather than your boiler.
Is the tool available now?
Not yet – it is in the architecture and not yet built. The framework on this page is the same one we use on the phone and you are welcome to work through it with us.
Does it apply to cylinders and oil tanks too?
Yes, with a difference: a leaking cylinder or a failed tank has no repair, because they are containment vessels. For those the question is when rather than whether.
Why will it not give me a price?
Because the answer depends entirely on which specific component has failed on which specific appliance, and a figure produced from a form would be fiction. We would rather help you ask the right questions.
Need this doing?
Call and describe the problem — you will speak to an engineer, not a call centre. Written quotes, no estimates over the phone.