No hot water diagnosis in Macclesfield
In short
Which parts of the house have no hot water, and whether the heating still works, narrows the fault immediately. Heating fine but no hot water on a combi points at the diverter valve; on a cylinder system it points at the zone valve, the cylinder thermostat or the coil.
Also called: hot water not working · lukewarm water · hot water runs out quickly · no hot water but heating works
Signs you need this
- No hot water at any tap but the heating still works
- Hot water only when the heating is on
- Water lukewarm however long the tap runs
- Hot water that runs out within minutes
- Hot water at some taps but not others
The first question is what kind of system you have, because the fault lists are completely different. A combi heats water on demand as it passes through a plate heat exchanger. A cylinder system heats stored water via a coil, controlled by a cylinder thermostat and a motorised valve. A third possibility — no heat source reaching the cylinder at all — often turns out to be a control or wiring fault rather than anything mechanical.
On a combi, heating working but no hot water is the classic diverter valve failure. The valve that switches flow between the heating circuit and the hot water exchanger sticks in the heating position. Lukewarm water that never gets properly hot, or hot water that fades after a minute, more often points at a plate heat exchanger silted up with magnetite — which is a system water problem showing itself in the boiler.
On a cylinder system, work outwards: is the programmer calling for hot water, is the cylinder thermostat set and calling, is the motorised valve opening, is the boiler firing in response. A failed motorised valve motor is extremely common and produces exactly the symptom of heating but no hot water. A failed cylinder thermostat produces water that is either always cold or dangerously hot.
Hot water that runs out too quickly is usually a sizing or reheat issue rather than a fault: a cylinder too small for the household, a thermostat set too low, a slow reheat from an undersized coil, or heat lost through poor insulation and uninsulated pipework. On older cylinders, a scaled or sludged coil transfers heat poorly and both reheat time and effective capacity suffer.
Lukewarm water on any system is worth taking seriously for a second reason. Stored water needs to reach 60°C to keep legionella bacteria from establishing, and a cylinder that never gets properly hot is a genuine risk rather than an inconvenience.
What the job covers
- Systematic diagnosis appropriate to your system type
- Combi diverter valve and plate heat exchanger testing
- Cylinder thermostat, motorised valve and wiring centre checks
- Immersion heater and backup heat source testing
- Cylinder coil performance and reheat assessment
- Repair, replacement and system cleaning where sludge is the cause
What it costs
We don't publish a price for this yet, because a number pulled out of the air is worse than no number at all — your plumber has to honour it. You'll get a firm price for your actual job when they ring you back, before any work starts. The quote itself is free and there's no obligation either way.
Common questions
Heating works but there is no hot water — what is it?
On a combi, usually the diverter valve. On a cylinder system, usually the motorised valve, the cylinder thermostat or the wiring between them. All are routine repairs.
Why is my hot water only lukewarm?
Common causes are a plate heat exchanger clogged with sludge on a combi, a cylinder thermostat set too low, a failing diverter, or a blending valve that has drifted. Lukewarm stored water is also a legionella concern, so it should not be left.
Need this doing in Macclesfield?
Tell us the job and it goes straight to our local plumber — one call back, usually the same day. Free quote, no obligation.