Pressure Relief Valve Dripping? We Replace It and Find the Cause in Shirley
We confirm the valve is passing, check why it lifted in the first place, and renew it so the system holds pressure safely again.
Booking fee plus hourly labour — the price is confirmed before any work starts.
What this costs
| Booked 14+ days ahead | £25 booking fee £85 per hour |
|---|---|
| Booked within 48 hours | £100 booking fee £65 per hour |
| Same-day call-out | £220 booking fee £45 per hour |
The booking fee secures the visit. Labour is then charged by the hour, so you only pay for the time the job actually takes.
Booking fee £25–£220
£25 + £85/hr booked 14+ days ahead, £100 + £65/hr inside 48 hours, £220 + £45/hr same day. Agreed before we arrive.
Covered under Pipework & Pressure
Heating & Radiators › Pipework & Pressure — one of 19 documented jobs in this section.
Same-day faulty pressure relief valve
Urgent jobs can often be booked for today. Ask when you book and we will confirm the slot before you pay anything.
15 service areas
Birmingham, Coventry, Dorridge and 12 more across the West Midlands.
What the Valve Is For
The pressure relief valve is a safety device. It is set to open at a pressure below the point at which pipework, seals and the boiler's heat exchanger could be damaged, usually around three bar on a domestic system. When it opens, water escapes through a discharge pipe to outside, reducing pressure. It is not part of normal operation, and it should close again once pressure falls.
Valves fail in two ways. They can stick shut, which is dangerous because the safety margin is lost, or they can fail to reseat, which shows as a continuous drip. Once a valve has opened, scale, grit or corrosion debris can sit on the seat and prevent a clean seal. The spring can also weaken with age. Either way, a dripping valve will not fix itself.
Why It Opened
This is the part that matters most. A relief valve opens because system pressure exceeded its setting, and the usual causes are:
- A failed or undercharged expansion vessel, so expanding water has nowhere to go.
- Overfilling, often after a repair, leaving pressure too high when cold.
- A filling loop left open or a valve passing, adding mains pressure continuously.
- A blocked connection to the expansion vessel, which behaves like a failed vessel.
- Less often, a fault in a pressure sensor or gauge giving a false high reading.
Replacing the valve without addressing these simply resets the clock. A new valve on a system with a dead vessel will open again at the next hot cycle.
Recognising the Signs
Look at the discharge pipe outlet, usually a copper pipe through an outside wall near the boiler. Staining, white deposits, green corrosion or a damp patch below it all indicate the valve has been passing. Inside, the gauge may swing from high when hot to low when cold, and the boiler may need topping up regularly. A single discharge event after overfilling is different from a valve that drips constantly.
What We Do on the Visit
We confirm the discharge is from the relief valve rather than a condensate pipe or a leaking joint nearby, which is a common misdiagnosis. We check the gauge at cold and hot, test the expansion vessel charge, confirm the filling loop is closed and not passing, and examine the valve and its seat. Where the valve is passing, we replace it with one of the correct pressure rating and size. We then refill, run the system and watch pressure through a full heat cycle to confirm it stays within range.
The Replacement Itself
Relief valves are usually screwed into a tee or the boiler's outlet assembly, and replacement means draining the relevant section. Access varies: an external valve on a system boiler is straightforward, while one inside a combi casing may take longer. We use the correct rated valve, not a generic substitute, because the setting is a safety parameter. Seals and washers are renewed at the same time. Parts are quoted separately and we confirm the specification before ordering.
Limits and What We Will Not Do
We will not remove a relief valve and blank the connection to stop a drip. That removes a safety device and puts the system at risk. We will not fit a valve of a different rating to stop it opening. And we will not promise that a replacement alone solves pressure problems if the vessel is faulty; we will explain the interaction and quote both if both are needed. If a gas-side component is involved, we stop and recommend a Gas Safe registered engineer, because Maintenance Men does not carry out gas work.
Safety Notes
If the valve is discharging and will not stop, switch the boiler off and let the system cool. Do not drain a hot system or open valves near electrical equipment. If the gauge is in the red zone when cold, do not run the boiler. A gas smell is an emergency: no switches or flames, ventilate if safe, leave and call 0800 111 999. A CO alarm means get everyone outside and call 0800 111 999.
After the Repair
Correct cold pressure, a charged vessel and a valve that seats properly should keep the system stable. We show you the gauge readings after the repair and explain what a normal hot reading looks like, so a recurrence is obvious. Checking the discharge outlet occasionally is a simple habit that catches a passing valve early.
Book a Relief Valve Repair
Tell us your boiler make and model, whether the discharge pipe is dripping, and what the gauge reads cold and hot. Our West Midlands diary occasionally has same-day space, which we will offer if we can but never promise. We take the booking fee up front, the hourly labour rate reflects how soon you need us, and the full cost is quoted and approved before work begins.
How the price works
We charge a booking fee to hold your slot, then an hourly rate for the work itself. The fee changes with how soon you need us; the hourly rate changes with the slot you choose. You approve the price before we start, so there is no surprise on the invoice.
Booked 14+ days ahead
£25 booking fee
then £85 per hour of labour
Best value. Book the slot now, pay the smallest booking fee.
Booked within 48 hours
£100 booking fee
then £65 per hour of labour
For jobs that can wait a day or two but not a fortnight.
Same-day call-out
£220 booking fee
then £45 per hour of labour
Urgent problems: standing water, no heat, no power, leaks.
Book the slot
Choose the window that suits you and pay the booking fee. That holds your place in the diary.
We diagnose on site
The engineer confirms the cause and tells you what the job involves and how long it should take.
You approve, we work
Nothing goes ahead until you agree the price. Labour is then charged per hour at your slot rate.
Water at the discharge pipe outside is a message from your heating system, not a minor annoyance. The pressure relief valve has opened because pressure reached its limit, and if it is now dripping continuously it has probably failed to reseat. We will replace the valve where needed and, just as importantly, establish why it opened so the new one is not forced to do the same thing.
What our customers say about our heating & radiators service
5 out of 5 from 10 reviews
Fast, tidy and friendly
Booked the £220 booking-fee slot on Tuesday and got a message confirming the time the same morning. The cause was explained, the price agreed before any work started, and the job was done in about 46 minutes. Clean and tidy when they left.
Job: No Heating from Boiler
Turned up when they said
What I appreciated was being told what was actually wrong before anyone started. Sorted in under 46 minutes and the invoice matched the quote to the penny.
Job: Expansion Vessel Fault
Exactly what was quoted
I had put off sorting this for months because I expected a runaround. Quoted the booking fee plus hourly rate upfront, stuck to it, and actually found the underlying cause rather than just clearing the symptom. Worked neatly and hoovered up afterwards.
Job: Airlock in Hot Water System
Book Faulty Pressure Relief Valve
Tell us what is happening and choose a slot. If you are not sure this is the right job, use the diagnosis panel — it narrows the problem down before you book.
- Booking fee confirmed up front
- Hourly labour, agreed before work starts
- Same-day slots for urgent problems
Questions people ask about faulty pressure relief valve
Straight answers to the things customers ask most often before booking.
Can I stop the drip by tightening something?
No. A relief valve is a sealed safety device with no user adjustment. Blanking it off or holding it shut removes the protection that keeps your system safe. It needs replacing by someone competent.
Why did the valve open in the first place?
Usually because pressure exceeded its setting: a failed expansion vessel, overfilling, a passing filling loop or a blocked vessel connection. We check those on the visit, because a new valve on an uncorrected system will simply open again.
Is a dripping relief valve urgent?
It should be dealt with promptly. It means the safety margin has been used and the system is losing water. Switch the heating off if it is discharging continuously and book a visit rather than ignoring it.
Do you replace the expansion vessel at the same time?
Only if testing shows it is faulty or undercharged. We quote it separately and explain why it is needed. Replacing a valve without checking the vessel is the mistake we are trying to avoid.
What will it cost?
The booking fee is paid when you book and the hourly labour rate depends on how soon you need us. You approve the full cost before work begins. The valve, vessel or any seals are identified and quoted separately.
Need faulty pressure relief valve sorted in Shirley?
Book a slot in the diary and pay only the booking fee up front. We confirm the rest before we start.