Frequently asked plumbing questions - answered
Updated: Mar 27
Got a problem with your boiler? Worried your heating system might have a fault? Read on... Here, our boss answers your top plumbing questions.
From bleeding radiators to topping up boiler pressure, we've got all the plumbing tips you need to know to keep your system ticking over safely and efficiently. Below, we've answered the most common, frequently asked plumbing questions.
FREQUENTLY ASKED PLUMBING QUESTIONS
Do I need to top up the pressure in my boiler?
The simple answer here is yes. Most modern, and some older, heating systems are completely closed, so the pressure on your boiler will need to be topped up manually. Generally, your boiler pressure gauge should sit around 1 bar when cold, so if it falls below or is consistently above 2.5 bar, you'll need to top it up. Read our guide on how to top up boiler pressure here.
How do I bleed a radiator?
You'll need to bleed your radiators if you suspect there is air trapped in the system at any point. To bleed a radiator, you'll need a radiator bleed key and some tissue or an old towel. Simply use the bleed key to turn the valve at the top of the radiator until you hear air being released, then prepare to catch any water that comes out at a result. We've written a full, step-by-step guide on how to bleed a radiator here.
How do I know what kind of boiler I have?
Generally speaking, there are three main types of gas boiler. The common names for these are combination boilers, system boilers and regular boilers (also known as conventional or heat-only boilers). Read our full guide to the different types of boiler here.
How do I make my boiler run more efficiently?
We spend more on our cars than we do on our boilers, and yet we use cars far less, and they tend to just burn a hole in your pocket. Instead of splashing out on that new BMW, consider investing in your heating system instead.
Regular servicing and financial investment are the two key ways to make your boiler run more efficiently, and ensure you're not left with any big maintenance bills. Heating system failures can be eye-wateringly expensive, so read our guide to keeping your boiler running efficiently here.
How do I use my immersion heater?
How to use your immersion heater depends on what type of hot water system you have. If you have a gas boiler and separate hot water cylinder, then the boiler will usually heat the hot water for you. In this instance, immersion heaters are only needed as a back-up.
If you have a fully electric heating system (for example: storage or panel heaters), then it is likely that your hot water is heated using an immersion heater. Read our guide to using an immersion heater in either scenario here.
How much is a new boiler?
The cost of a new boiler or heating system really depends on your needs. We can work with almost any reasonable budget, but we always aim to give the right long-term advice to all of our clients. We want to save you money in the long run by expertly installing a reliable heating system. We'd suggest budgeting around £2,500 to £3,000, but for full details read our guide, where we've broken down pricing and costs for new boilers and heating systems.
How often should I have my gas appliances serviced?
It's generally recommended that you have your gas appliances serviced annually, though for private homeowners there is no legal requirement. For landlords, it's a legal requirement to have your property's gas appliances (including boilers, hobs and fireplaces) inspected at least once every 12 months. A record of this inspection must be kept by the landlord and gas engineer, this is called a gas safety certificate. Read our guide to gas safety inspections here, and learn more about gas safety in this useful article.
What is a power flush and do I need one?
A power flush essentially cleans your whole heating system. We use purpose built power flushing pumps alongside large magnetic filters, designed to cure the circulation and boiler noise problems caused by accumulations of sludge, corrosion deposits and scale which are found in most ageing central heating systems.
You'll need to organise a power flush of your heating system every five to six years to keep it in top condition, or an engineer will power flush your system when a new boiler is installed in line with the BS7593:2006 Code of Practice. Get more information about power flushing here.
What is the difference between a combi boiler and a condensing boiler?
This is one of the most common plumbing and heating questions we get asked, and it's one of the most confusing. Many people confuse the term 'condensing boiler' with combi (or combination) boiler. Today, all gas and oil boilers in the UK are condensing boilers, as the definition of a condensing boiler is simply one that creates condensation when it's in use. There are three different types of boiler today: a combination boiler, a system boiler and a regular boiler. Find out what type of boiler you have here.
What is the difference between a service and a landlord's gas safety inspection?
It's a legal requirement for landlords to have a gas safety inspection carried out on their gas appliances once every 12 months. Private homeowners are not required to have their gas appliances checked, but it's recommended that you have them serviced annually to ensure they're safe and in working order. Here's our guide to gas safety inspections vs servicing.
What is the difference between a vented and unvented cylinder?
The difference between these two types of cylinder is fairly straightforward. A vented cylinder is one which is fed from a storage cistern above it (often located in the loft). An unvented cylinder is one which delivers mains-pressure hot water. Read more about vented and unvented cylinders here.