What Size Temporary Boiler Do I Need?
A quick guide to sizing a temporary boiler, from 90kW to 600kW, and what to have ready when you call us for a quote.
Start with the boiler you already have
It is the first question we ask on almost every call, and the one people are least sure about. The good news is that you do not need a heat loss calculation to get a temporary boiler on its way. In most cases the boiler you already have tells us most of what we need to know.
Look at the data plate on the existing boiler, or in the plant room log book. Its output in kW is the best starting point, because the heating system was designed around it.
If there is more than one boiler, check how many have actually failed. A plant room with three 150kW boilers and one of them down does not need 450kW of hire plant. It may only need cover for the missing 150kW.
Matching your boiler to our range
As a rough guide:
- Up to 90kW: the 90kW Dual Fuel, which suits surgeries, small offices, village halls and churches
- 90kW to 200kW: the 200kW Twin Oil, or the 250kW Gas Fired where there is a gas supply
- 200kW to 300kW: the 300kW Gas or Oil
- 300kW to 400kW: the 400kW Dual Fuel
- 400kW to 600kW: the 600kW Gas or Oil
- Hot water only: the Hot Water Only boiler
- Over 600kW: more than one unit, or a packaged temporary plant room, sized against the building's actual heat load
We always confirm the size with you before anything leaves the yard.
Leave some headroom
A hire unit that has to run flat out for the whole hire is undersized. If your existing boiler sits right at the top of one of the bands above, the next size up is usually the safer choice. It is how a temporary installation avoids struggling in the coldest week of the job.
Heating, hot water, or both?
If the boiler that has failed also heats a hot water cylinder, the hire unit needs to cover both. In hospitals, care homes and leisure centres, hot water is often the more urgent of the two. Tell us early, because it can change which unit we send.
What fuel is on site?
The range covers natural gas, oil and dual fuel. If there is a gas supply we can connect to, a gas-fired unit may suit. If not, an oil-fired or dual fuel boiler is the answer, and we hire a 3,000 litre bunded oil tank alongside it, delivered on the same visit. As a guide to running costs, the 90kW uses around 10 litres of gas oil an hour at full output.
Where will it go?
Temporary boilers sit outside the building, so it helps to know:
- where the unit can be parked, and how far that is from the plant room
- the access route for delivery, including gate widths, height limits and kerbs
- whether there are connection points on the flow and return, or whether we will need to make them
- what power supply is nearby (the 90kW runs from a 16A supply or a standard 13A plug)
Units up to 200kW can be lifted into position by HIAB where a trailer cannot be reversed up to the plant room. Photographs of the plant room and the outside area are a big help when you call.
Planned works or emergency?
For planned works, such as a boiler room replacement, we can survey the site and size the unit properly in advance. In an emergency, we size from what you tell us on the phone and aim to have heat back on the same day.
Not sure? Just call
If you cannot find the data plate or do not know the output, call us anyway. We will work it out with you from the building type, its size and what the heating serves.
Call 01782 274537 for a quote, or 0800 644 6240 for emergency hire, 24/7, 365 days a year. You can also request a quote online or see the full boiler hire range.