Does this sound like an old boiler problem?

[Tellytibby]

Hot tap in the kitchen only runs extremely hot when turned as far as it will go, but when turned to a lower pressure that isn't like a jet stream it will only run cold (so makes washing up a bit tricky). Showers also run hot for around a minute then goes cold for about 15 seconds then hot again (repeats for as long as the shower is on). Water for the bath will only run warm, so no hot baths despite water in kitchen being boiling.

Boiler was fitted in 2013.

Do you have a hot water tank?

I'd check my pressure on the boiler first. It should be about 1.5 bar. It could also be a faulty thermostat.

If you have a combination boiler it could be two issues. Do you know which model you have?

No. Combi boiler.

Not home atm but I know it's Main

Pressure is good

Sounds like the flow sensor is only partially working.

When you turn on the hot tap the boiler senses the flow of water, knows that the water needs heating and heats it.

Maybe the flow sensor transducer, the wire connecting it to the control board or the control board itself.

I would google the boiler make and model and look on the web for similar issues that people have experienced.

10 year old boiler is a bit of a problem. Too young really for replacement, too old to justify an expensive repair. These days a lot of techs just replace the whole unit rather than go inside and look for problems.

I'm basically really worried it needs replacing. Because if it does my landlord will likely put my rent up as it's so expensive to get a new boiler.

Well unfortunately no one can really tell until someone looks at it, diagnoses the problem and fixes it (or not).

Sometimes things are easy to fix/replace. Sometimes they aren't. It depends on the part, the make of boiler etc. Sometimes stuff is very easy to do, other times it is difficult for various reasons.

Flow sensor or limescale in heat exchanger

What's that guy called on here who is always really helpful with stuff like this.

What is the make and model of the boiler my DH is an ex gas engineer he might be able to offer advice until that fella is tagged.