Why is my boiler losing pressure?

Why is my boiler losing pressure?

There are several potential causes for your boiler losing pressure. Here are some of the usual suspects:

Water leaks

If water is escaping from your central heating system, it's likely to cause a drop in pressure. Even small leaks, from radiators, pipework, or the boiler itself, can result in a slow but steady loss of pressure over time. If you find a leak, it's important to fix it as soon as you can to prevent further issues.

Air in the system

If you notice that your radiators aren't heating evenly or are making strange gurgling noises, it might be that there is air trapped in the system. This can cause an imbalance in pressure. Thankfully, it's easily remedied. Using a radiator key, bleed all the radiators to let any air out and restore the optimal pressure levels.

Faulty pressure relief valve

Your central heating's pressure relief valve is designed to prevent damage to the system by automatically releasing excess pressure. If the valve is damaged or faulty, it may be releasing pressure unnecessarily, which will cause recurring low pressure in your boiler.

Boiler gremlins

If there are no signs that the pressure loss is due to the above reasons, there may be a more fundamental problem in your central heating system. At this stage, your best bet is to arrange for a heating engineer to take a look. Faulty expansion vessels or a damaged heat exchanger are other potential gremlins that they will want to investigate.

Why is my boiler losing pressure when the heating is on?

If your boiler pressure drops when the heating is on, there may be a problem with your boiler's expansion vessel. The expansion vessel absorbs pressure fluctuations in the system. If it packs in, it can result in a rapid loss of pressure in your boiler. A faulty expansion vessel often requires professional repair or replacement. Small leaks can also become more pronounced when the system heats up.

What do I do if my boiler pressure keeps dropping?

We suggest you take the following steps if you find that your boiler pressure has dropped:

1. Repressurise the boiler

If you know how to, use the filling loop to top up the system. This should repressurise your boiler and fix the issue, at least temporarily. If the pressure drops again within hours or days, it's time to investigate further.

2. Bleed your radiators

In case the pressure drop is due to air being trapped in the system, it's good practice to bleed your radiators. Use your radiator key to gently open the valve and listen for any air escaping. If none is present, move to the next step.

3. Check the pressure release valve

If you know where to locate it, have a quick check of the pressure release valve. If it's constantly releasing pressure, you may have found your problem. Unless you have the know-how to repair or replace it yourself, this job is best left to a heating engineer.

4. Hunt for leaks

If the pressure has dropped and there's no sign of any air in the radiators, it's time to investigate for any sign of leaks. Given that pipes are often hidden away under floorboards and behind cupboards, it can be difficult to diagnose leaks, but look out for damp patches or stained walls near pipes or radiators.

5. Call a professional

If, after the above checks, you're still none-the-wiser about your pesky pressure drops, it's time to call in the pros.

Repair your boiler with Koziwarm

If you've got a problem with your boiler, get in touch with us here at Koziwarm or call us on 0191 262 8000. We're a respected family-run business with over 40 years of installing, repairing, and maintaining gas boilers all over the North East. Our experienced and trustworthy engineers can provide a diagnosis of any boiler faults and ensure a swift repair.