The Ideal Logic Max C35 is the biggest combi in Ideal’s Logic Max range, giving 14.5 litres of hot water per minute with an Ideal System Filter in the box. It still fits inside a standard kitchen cupboard, and it’s aimed at three and four bedroom homes, usually with a main bathroom and an en suite.
The Logic Max is still on sale. The current model is the second-generation Logic Max Combi2 C35, which kept the same outputs as the first Logic Max and added a larger colour screen. If you own an earlier Logic Max C35, most of this review applies to your boiler too.
What Are The Ideal Logic Max C35’s Key Specs?
The Logic Max C35 gives 35.3kW for hot water, 24.2kW for heating and 14.5 litres per minute, with a system filter included.
| Specification | Ideal Logic Max C35 |
| Boiler type | Combi |
| Fuel | Natural gas |
| Hot water output | 35.3kW |
| Central heating output | 7.1 to 24.2kW |
| Hot water flow rate | 14.5 litres per minute (35°C rise) |
| ErP rating | A for heating, A for hot water |
| Seasonal heating efficiency | 94% |
| NOx class | Class 6 |
| Dimensions | 700mm high x 395mm wide x 278mm deep |
| In the box | Ideal System Filter |
| Status | Current, sold as the Logic Max Combi2 C35 |
What Is The Ideal Logic Max C35?
It’s the largest size in the top tier of Ideal’s Logic family. Ideal sells its Logic boilers in three tiers: Logic, Logic+ and Logic Max.
All three use the same compact chassis and the same three sizes. The Logic Max is the only one supplied with an Ideal System Filter as standard.
The C35 has the highest hot water output in the range. Its heating output, though, is the same 24.2kW as the C24 and C30, which surprises a lot of people. The bigger number on the badge is all about hot water, and that’s what decides how well a combi copes in a busy household.
It’s a condensing boiler, made in Hull. It modulates down to 7.1kW, so it can tick over gently on mild days instead of cycling on and off.
How Does The Logic Max C35 Compare With The Logic+ C35?
They’re the same boiler on paper, and the only real difference is that the Logic Max comes with a system filter. Both have 35.3kW for hot water, 24.2kW for heating and 14.5 litres per minute.
A magnetic filter traps the black sludge (iron oxide) that forms inside radiators and pipework. That sludge is one of the most common causes of blocked heat exchangers and noisy boilers we see.
You can add a filter to a Logic+ install, and any good installer will. With the Logic Max, it’s part of the boiler you buy.
Comparing a Logic Max quote with a Logic+ quote? Check whether the Logic+ price includes a filter. Once it does, the gap is usually small. Our Ideal Logic+ C35 review covers that model in more detail.
What Features Does The Logic Max C35 Have?
You get a system filter in the box, the strongest hot water flow in the Logic Max range and a large colour screen.
- Ideal System Filter supplied with the boiler
- 14.5 litres per minute of hot water
- Large colour screen on the current Combi2 model
- Compact cupboard fit, with a low lift weight
- Serviceable from the front
- Built-in frost protection
- Compatible with Ideal’s Halo smart thermostat and most mainstream controls
- Service reminder on the display
How Efficient Is The Ideal Logic Max C35?
It’s A-rated for heating and hot water, with 94% seasonal heating efficiency. Most of the energy in the gas ends up in your radiators and taps.
Two things decide whether you actually see those figures at home.
The first is flow temperature. A combi running radiators at 75°C or 80°C will rarely condense, and turning it down to around 55°C to 60°C, where your radiators allow, makes a real difference. The second is a clean system, which is where the included filter earns its place.
Good controls help too. A smart thermostat lets you set schedules from your phone and stops the boiler heating an empty house. For landlords, it also means fewer calls about a cold flat.
What Are The Pros And Cons Of The Logic Max C35?
It has the best shower performance in the Logic Max range, but heating stops at 24.2kW.
Pros
- Best hot water flow in the Logic Max range
- Filter included, so the system is protected from day one
- Same small case as the smaller models
- A-rated, quiet and simple to use
- Current model, so parts and support are easy to find
Cons
- Heating output is limited to 24.2kW
- Uses an aluminium alloy heat exchanger, while the Vogue Max uses stainless steel
- Two showers at once will still feel the strain
- Often needs a 22mm gas supply, which can add to the installation cost
What Size Home Does The Logic Max C35 Suit?
It suits a three or four bedroom home with a bathroom and an en suite that aren’t used heavily at once. It runs one shower very well and leaves enough headroom for a basin or kitchen tap.
With two full bathrooms in use at once, a combi is rarely the best answer.
A system boiler with an unvented cylinder stores hot water, so several outlets can run together. Our best system boilers guide covers the options.
At the smaller end, a two or three bedroom house with one bathroom may only need the C30. Our Ideal Logic Max C30 review explains where that model fits. As with any combi, your mains water supply sets the limit, so we test flow and pressure before recommending a size.
How Much Does A Logic Max C35 Cost To Install In 2026?
Expect a guide price of £2,100 to £2,900 for a like-for-like swap, including VAT. Relocations and conversions from a system or regular boiler cost more.
| Type of job | Guide installed price |
| Like-for-like combi swap, same position | £2,100 to £2,900 |
| Combi swap with boiler relocated | £2,700 to £3,600 |
| Conversion from system or regular boiler to combi | £3,200 to £4,500 |
Treat these as a starting point. Your actual price depends on the flue, gas pipe size, where the boiler goes and the controls you pick.
A fixed quote should cover the boiler, flue, filter, system cleanse, controls, removal of the old boiler and all registrations. You shouldn’t face extra charges on the day unless something unexpected turns up and is agreed with you first. Our guide to how much a new boiler costs gives more context.
What Are The Best Alternatives To The Logic Max C35?
For larger homes, the Vogue Max C32 or C40 is the natural step up, with more heating output and a stainless steel heat exchanger.
- Ideal Vogue Max C32 or C40: Ideal’s premium combis, with stainless steel heat exchangers and heating outputs of 26kW and 32kW. Good for larger homes. See our Vogue C26 review for an introduction to the range.
- Ideal Logic+ C35: the same outputs, without the filter included.
- Worcester Bosch Greenstar 4000 or 8000: if you’d prefer a Worcester, our Worcester Bosch vs Ideal comparison sets out how the two brands differ.
- Larger combis: for high hot water demand, our best 40kW combi boilers roundup is a useful next read.
Is The Ideal Logic Max C35 Worth It?
Yes, for a family home with a bathroom and an en suite. You get strong hot water flow, a filter in the box and a compact boiler that’s easy to fit and maintain.
If your home needs more than 24kW of heating, or you want stainless steel, step up to the Vogue Max. For a side-by-side look at the whole range, see which is the best Ideal boiler.
Choose It If
- You have a three or four bedroom home with a bathroom and an en suite
- You want the strongest shower performance from a compact Ideal combi
- You want a system filter included as standard
- The boiler has to fit inside a kitchen cupboard
Look Elsewhere If
- Two bathrooms are often in use at the same time
- Your home needs more than 24kW of heating output
- You’d prefer a stainless steel heat exchanger
- Your mains water supply is weak, which would limit any combi
Get A Free Boiler Quote From Clever Energy Boilers
We fit Ideal boilers for homeowners and landlords across the North West, Yorkshire and the Midlands. Our engineers are experienced, professional and registered installers.
We size every combi from your home’s real heat loss and hot water use.
See our Ideal boiler installations page for more on how we work, or get a fixed boiler quote online today. We can also set you up with long, market-leading warranty cover through Clever Energy.
If the Logic Max C35 isn’t the right fit, we’ll recommend one that is.
Frequently Asked Questions
Is The Ideal Logic Max C35 Still Available?
Yes. It’s sold today as the Logic Max Combi2 C35, with the same 35.3kW hot water output and 14.5 litre per minute flow rate as the first-generation model.
What Is The Heating Output Of The Logic Max C35?
It’s 24.2kW, modulating down to 7.1kW. The 35kW figure applies to hot water only.
Can The Logic Max C35 Run Two Showers?
Not well. It can manage a shower plus a tap, but two showers at once will share 14.5 litres per minute and both will feel weaker. A system boiler with a cylinder suits that kind of demand better.
What Comes In The Box With The Logic Max C35?
An Ideal System Filter comes with the boiler. The flue and controls are chosen separately to suit your property.
How Often Does The Logic Max C35 Need Servicing?
Every year, by a Gas Safe registered engineer. Annual servicing keeps it running safely and efficiently, and our Clever Care servicing plans make it simple.