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Advanced Knowledge Centre

My boiler keeps losing pressure

Heating, How-to

boiler losing pressure

Help! My boiler keeps losing pressure

If your boiler keeps losing pressure it’s probably showing F22 or F75 faults, then this article and video will help you.

When a boiler shows an F22 or F75 fault, then most probably repressurising and resetting the boiler will restore your boiler back to working order.

How to repressurise and reset your boiler

Watch the videos to see how to repressurise
and reset your boiler.

Description of what to do given below too.

Video 1 – How to solve the F22 fault code

boiler keeps losing pressure F22 fault

Video 2 – How to solve the F75 fault code

boiler keeps losing pressure F75 fault

Quick Guide to resolving boiler pressure loss issues

Time needed: 30 minutes.

3 Steps to checking why your boiler keeps losing pressure

  1. Re-pressurise

    Locate the fill valve of your boiler and repressurise your boiler system to 1 Bar. This usually gets your system up and running again.

  2. Check for leaks

    Check all radiator valves for leaks as well as underneath the boiler for any signs of water leaks. If there are signs of leakage, then call a gas-safe registered heating engineer like us.

  3. Check the safety discharge pipe

    Locate the safety discharge pipe work outside your property and check for any leakage. It’s a small pipe which can only be seen on the outside wall of where your boiler is installed. If this pipe is dripping or water running from it, then this is an indication of one or more faults with PRV (pressure relief valve), faulty pressure gauge , filling loop or filling valve and/or expansion vessel.

  4. If you’re unable to resolve the problem of your boiler losing pressure

    Then call a gas-safe registered boiler engineer (like Advanced Heating & Plumbing 0800 328 0449) who can call out same day and have your boiler system working again.

If your boiler or central heating keeps losing water pressure, then you’re in the right place. Here’s a handy guide to help you try to resolve the problem yourself, with your own boiler.

Does your boiler or central heating have a problem with losing pressure?

  • Is your boiler constantly losing pressure? Weekly, daily or even hourly?
  • Is your boiler making strange, worrying or frightening noises?
  • Does your boiler keep giving you fault codes to re-pressurise the system?
  • Does the “low pressure” light keep coming on?
  • Is the heating not getting up to the temperature you set?
  • Is the central heating or hot water (or both) not working as they should be?
  • Does the pressure keep rising, then drops to nothing?
  • Does your pressure gauge keep going down?
  • Do you have to keep resetting your boiler when the pressure drops?

The first thing to do is try to not worry too much about this problem – you can attempt to resolve your boilers’ pressure loss yourself using the tips below. But if find that you need expert help, then call us as we can resolve most boiler pressure issues same day. At Advanced Heating & Plumbing we employ gas-safe registered heating engineers. We’re only a phone call away.

Boiler or Central Heating Pressure Loss – 3 Problems and Remedies

#1 – Boiler Re-Pressurisation

  • Find your “fill valve”, then re-pressurise your boiler system to 1 Bar – this should get your system up and running again. Check the boiler manufacturer’s instruction manual, left with your boiler (or look online). This should give full instruction on how to refill the system.
  • If you can’t find or locate your boiler manual, contact us. We’ll be more than happy to assist either over the phone or via appointment with a service engineer.
  • Important note: it’s bad for the boiler if you keep replacing the water. This could lead to other parts of the boiler needing to be replaced.

#2 – Check for leaks around the central heating system

  • Check all radiator valves for leaks – just a small drip can make your boiler lose pressure over the course of a few hours
  • Check the boiler underneath for any signs of water leaking

#3 – Check the safety discharge pipe

  • Check the safety discharge pipe work for leaking OUTSIDE the property.
  • There is a safety discharge pipe that lets water out of the boiler, if there is a problem with the boiler becoming over pressurised. It will begin to drip or run with water. This is called the Pressure Relief Valve Discharge Pipe (or commonly called the “P.R.V”)
  • It’s a small pipe, which can only be seen on the outside wall of where the boiler is installed.
  • If your pressure relief valve is leaking, it could mean that you have one (or more) of the following problems.

Problem: Your Pressure Relief Valve needs replacing – it’s become weak on holding back the pressure

Remedy: Install a replacement P.R.V.

Problem: Too much pressure has been put into the system. You could have a pressure gauge that’s not giving a correct pressure reading and now, due to over-pressurisation, the pressure relief valve (P.R.V) is faulty and needs replacing.

Remedy: Install a replacement P.R.V and possibly a new Pressure Gauge

Problem: A faulty filling valve is not shutting off correctly, so the water pressure is getting too high in the boiler.

Remedy: Install a new Filling Loop or Filling Valve

Problem: There’s oxide sludge in the system which has damaged the Pressure Relief Valve (P.R.V.)

Remedy: Power Flush the central heating system and install a new P.R.V.

Problem: If the expansion vessel, which allows the system’s water to expand, is faulty, the pressure will rise dramatically when the boiler is running. The P.R.V. will then automatically keep dumping the water in the system to the outside.

Install a new Expansion Vessel and a new P.R.V.

Boiler Losing Pressure Problem Still Not Fixed?

If you’re unable to resolve the low pressure problem(s) with your boiler, don’t despair! Advanced Heating & Plumbing have skilled gas-safe engineers that can be with you the same day to give you a no-obligation quotation to repair most boiler problems, with a guarantee on all works.

Book your appointment by contacting us today.

Disclaimer: The information contained on this website if for general information purposes only. You should not rely upon the material or information on the website as a basis for making any decisions or actions and we don’t accept liability for anything you chose to do with the information.