A heating system is considered an essential piece of equipment to many establishments and residential areas. Some even rely on boiler hire services if they have any emergencies where their boiler broke down all of a sudden. For that very reason, some prefer to keep spare parts for their boiler’s critical components. This is a great way to save downtime and immediately resolve any issues with your boiler. We break down some essential boiler spare parts that every boiler operator should have on hand.

Flame Detector

This is perhaps one of the most common spare parts to keep as it can cause quite a lot of trouble if your flame detector needs to be replaced. From home furnaces to sizeable industrial water tube boilers, basically, all boiler types require this piece to function properly. A flame detector is designed to prevent the equipment from filling with raw fuel when a flame doesn’t exist. Flame detection comes in many forms, but they all function the same. Large boilers often have a ‘flame scanner’ while a ‘flame rod’ works in most commercial boiler applications.

Flame detectors essentially make sure your equipment is safe to run. The sensitive nature of these devices definitely makes their spare parts a must-have in case of an emergency.

Pressure Control Device

A pressure control device can be usually seen as a standalone ‘pressure controller’ for smaller heating systems. In larger systems, they come as a part of the PLC-based controller. Without a pressure control device, an operator would have to watch the boiler pressure gauge and manually adjust the boiler firing rate to maintain system pressure. 

Depending on the installation, this can be a difficult task and can be quite an inaccurate way of controlling the pressure. It helps a lot if you have a spare pressure sensor and loop controller. A spare PLC on hand that’s been preloaded with the required software is also considered to be essential.

Safety Relief Valve

Safety relief valves are designed to relieve an excessive buildup of pressure inside the boiler. Since this is a huge safety concern, safety relief valves are required by code to be tested annually. As a workaround, some commercial establishments opt to have a spare set of valves that can be rotated in at the scheduled annual testing. So, even if the valves in operation are being tested for certification, you still have a spare to work with. Even boiler rentals have their own set of spare valves for safety.

However, safety valve springs do tend to degrade over time, causing the valve to vent out even when pressure is not at a set point. It’s in situations such as this that having a spare valve can come in handy. Remember, getting new valves sized for your boiler at your set points can take a couple of days to complete, so it’s always a good idea to have spares.


Whether you’re in urgent need of spare parts for a quick fix or you simply want to ensure you have backups when you need them, having boiler spare parts is never a bad thing. What matters is you lessen the downtime when something goes wrong.

London Climate Hire is here to solve all your boiler-related problems. Our experienced engineers specialise in installing temporary boiler hire and heater rentals in London and local counties. We’ll get you back up and running in no time. Contact us if you need 24/7 emergency boiler hire services!