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Fast diagnosis and repair of boiler leaks across Hull.

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HomeBoiler RepairsBoiler Leaking

A leaking boiler needs fixing immediately. Water dripping from the boiler, pooling underneath, or running down the wall isn't normal and it's not safe. Leaks can damage electrics, rot floorboards, and if left long enough, cause the boiler to fail completely. Most leaks come from failed seals, corroded heat exchangers, pressure relief valves venting, or loose pipe connections Common across Hull, from Spring Bank to Newland Avenue.

In Hull's hard water areas around Cottingham and Wollaton, limescale accelerates corrosion and seal wear.

We diagnose and repair boiler leaks same day. Our Gas Safe engineers trace where the water is coming from, whether it's the boiler itself or the pipework connected to it. We carry common seals, pressure relief valves, and expansion vessels on the van. Simple leaks are fixed in under an hour.

Where Boilers Leak From

Identifying where the leak is coming from helps us fix it faster:

Pressure relief valve

This safety valve vents water when pressure is too high. If it drips constantly, the system pressure is set too high or the valve itself has failed and won't seal.

Pump seals

The circulation pump has seals that can perish over time. Water drips from the pump body. Replacing the seals or the entire pump fixes it.

Heat exchanger

The most serious leak. The heat exchanger corrodes from inside, especially in hard water areas. It leaks from the seams or pin holes in the metal. Repair isn't possible, heat exchanger replacement costs more than a new boiler.

Pipe connections

Compression fittings and soldered joints can leak if they work loose or corrode. Usually fixable by tightening or remaking the joint.

Automatic air vent

This small valve on top of the boiler bleeds air automatically. The internal float can stick open, leaking water. Replacement is simple and cheap.

Condensate trap

Condensing boilers have a trap that collects condensate. If it cracks or the seal fails, water leaks from underneath the boiler.

What to Do If Your Boiler Is Leaking

1

Turn off the boiler

Switch it off at the controls and at the mains. A leaking boiler shouldn't keep running, water and electrics don't mix.

2

Mop up the water

Use towels to soak up any water that's pooled. Check the floor underneath for water damage. If it's near electrics, isolate the power.

3

Check the pressure gauge

If pressure is above 2 bar, the pressure relief valve might be venting. Turn off the filling loop valves to prevent more water entering the system.

4

Don't try to fix it yourself

Boiler repairs require a Gas Safe engineer. DIY fixes can make it worse or create safety issues. Call us, we'll diagnose and repair it properly.

How We Fix Boiler Leaks

We trace the leak methodically and fix it properly:

1

Locate the source

We dry the boiler case and watch where water appears. Leaks often run down and drip from the lowest point, not where they originate. We trace it back to the actual source.

2

Check system pressure

High pressure causes the relief valve to vent. We check the gauge and test the expansion vessel. A failed expansion vessel makes pressure rise to unsafe levels.

3

Inspect seals and joints

We check pump seals, pipe connections, and the automatic air vent for leaks. These are the most common sources and are usually fixable.

4

Test the heat exchanger

If water is leaking from inside the boiler casing with no obvious external source, the heat exchanger is suspect. We inspect it with a torch and mirror, looking for corrosion or pin holes.

5

Repair or replace parts

We fit new seals, tighten joints, replace pressure relief valves or air vents, or fit a new expansion vessel. We test under pressure to confirm the leak is fixed.

6

Advise on heat exchanger leaks

If the heat exchanger is leaking, we'll price up replacement vs a new boiler. Heat exchangers cost £400-£800 plus labour, often more than the boiler is worth. We'll give honest advice.

Upfront prices, no nasty surprises

We'll always tell you the cost before we start. These are typical price ranges, your exact quote depends on the job.

ServiceTypical Cost
Leak diagnosis (free with repair)£0
Pressure relief valve replacement£85-£140
Pump seal or pump replacement£120-£250
Expansion vessel replacement£140-£220
Heat exchanger replacement£400-£800

All prices are estimated. Final costs depend on the specific job. We provide detailed quotes before starting work.

Got questions? Here's the quick answers.

How much does it cost to fix a leaking boiler in Hull?
Simple fixes like pressure relief valves cost £85-£140 across Hull and surrounding areas. Pump replacements cost £120-£250. Expansion vessels cost £140-£220. Heat exchanger replacement costs £400-£800, at which point a new boiler often makes more sense.
How long does boiler leak repair take?
Simple seal or valve replacements take 30 minutes to 1 hour. Pump or expansion vessel replacement takes within 2 hours. Heat exchanger replacement takes 3-4 hours, whether you're in Newland Avenue, Cottingham, or Spring Bank.
Is a leaking boiler dangerous?
Yes, water leaking near electrics is a fire risk. A leaking heat exchanger can also indicate corrosion that might lead to gas leaks. Turn the boiler off and call us immediately.
Why is water dripping from the pressure relief pipe outside?
The pressure relief valve is venting because system pressure is too high. This is usually caused by a failed expansion vessel or the filling loop being left open. We'll test the expansion vessel and fix it.
Can a leaking boiler be repaired or does it need replacing?
Most leaks can be repaired. Pump seals, pressure valves, and pipe connections are all fixable. Only heat exchanger leaks are usually terminal, and even then, we'll price up repair vs replacement so you can decide.
Will my boiler leak get worse if I ignore it?
Yes, small leaks become big leaks. Water damages the boiler PCB, corrodes other components, and risks electrical faults. Fix it now before it causes more damage.
Why is there water pooling under my boiler?
Something is leaking: pressure relief valve, pump seal, pipe connection, or condensate trap. We'll dry it off, trace where the water is coming from, and fix the leak.
My boiler is leaking from inside the casing, what's wrong?
Likely the heat exchanger, automatic air vent, or an internal pipe connection. We'll open the casing, inspect all components, and identify the source. Heat exchanger leaks are serious and expensive to fix.
Can I still use my boiler if it's leaking?
No, turn it off immediately. Running a leaking boiler risks damaging electrics, creating short circuits, and making the leak worse. Call us, we'll come out same-day.
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