The Best Heat Only Boilers, Prices and More [2021 Buyer’s Guide]

Welcome to our 10-minute guide covering heat only boilers. Here, we’ll explain what heat only boilers are, talk about purchase prices, the cost of installation, and offer recommendations for the best brands producing heat only boiler ranges.

NEED A NEW BOILER? If your heat-only boiler breaks often and you’re considering a replacement, you can get a fixed-price quote by filling in this 90-second questionnaire from Heatable.

What Is a Heat Only Boiler?

A heat only boiler goes by several names, including “traditional”, “regular”, and more commonly, “conventional”. 

If your property uses a heat only boiler, the central heating system will be linked to both a hot water storage tank (or cylinder), which is fed by a cold-water storage tank.

Which Heat Only Boiler Should You Buy?

There’s plenty of false economy in the heating industry. So, it’s worth being wary of cheap brands, particularly when they offer a short warranty. Since the boiler itself only makes up 35% of the installation cost, saving 10-20% on a cheaper model makes little difference to the what you’ll pay overall.

We usually advise investing in the best boiler possible. Doing so will reduce long-term repair costs, and get you an appliance that’s more efficient than a cheaper equivalent.

The Best Heat Only Boilers

There’s little point suggesting an actual boiler model, like the Ideal Logic+ 18kW, for instance. That’s because, even with a rough idea about your property size, it’s hard to determine the exact kW boiler you need.

However, what I can do is offer up some recommendations, based on the best sellers at my time working for an independent plumbing merchant.

Worcester Greenstar RI

If you’re in the market for a Worcester heat only boiler, you’ll want to head for their Greenstar RI range.

Now, note that a Worcester Bosch warranty is sometimes tough to nail down. For a start, it constantly changes alongside their promotions.

So, you can expect to get a 5-year warranty as standard with the Greenstar RI. That said, do speak to a Worcester Accredited engineer to determine if there’s a better warranty on offer. Sometimes, warranties can be extended by using a Worcester Accredited engineer and fitting Worcester-branded parts (such as heating controls and boiler filters).

As an example, Heatable can offer a warranty up to 10 years, and their boiler installation costs are extremely competitive. Use Heatable’s clickable form to find out what deals are currently on offer.

Ideal Logic+ Heat Only

Ideal Boilers are a British manufacturer producing top quality boilers at low prices. Compared to the Vaillant and Worcester Bosch picks on this list, this Ideal heat only boiler is DIRT cheap.

What kind of fuel does your boiler use?

Grab your fixed price online by 3PM, and get next-day boiler installation.

Worcester boilers installed from as little as £1,795.

With the Logic range, it’s crucial that you choose the Plus model. The features and efficiency are similar to the standard Logic, but the warranty is where the big difference lies. The Logic Heat gets you only 2 years of coverage, whereas the Logic Heat Plus comes with 7 years, and the price difference is trivial – it’s worth it.

That said, both the Logic and Logic Plus offer a 10-year warranty on the heat exchanger — one of the most expensive boiler parts.

Vaillant EcoTec

The EcoTec range is better known for combi models, but you’ll find Vaillant heat only boilers in this range, too. If your fitter is suggesting a Vaillant EcoTec, we’d be inclined to listen to them.

With the EcoTec, you’ll pay a little more than you would compared to an Ideal heat only boiler. But there’s plenty of choice with 12, 15, 18, 28, 30 and 38kW outputs from Vaillant’s 412, 415, 418, 424, 430, and 435 models.

The Vaillant heat only boiler offers you a basic 5-year warranty. This can be extended to 7-years, but the appliance HAS to be fitted by a Vaillant Accredited Engineer.

How Do Heat Only Units Differ From System Boilers?

A system boiler works much like a heat only boiler. It, too, has a hot water storage cylinder; however, a system boiler doesn’t require a cold-water feed tank. This tank is usually located in your loft, and takes up a fair bit of space.

So, if you see a cylinder but not a cold-water storage tank, you need to go and check out our guide to system boilers — that’s the type of boiler you have.

Why Would a Property Have a Heat Only Boiler, Not a Combi?

Heat only boilers are typical of an old central heating system. Newer setups, on the other hand, usually utilise the less cumbersome combi boilers.

But there is a place for both combi and heat only boilers. Thanks to the water storage facility, heat only boilers don’t need to heat hot water on demand like a combi does. That means you have hot water “on-tap”.

The BIG downside is that heat only boilers take up lots of room. In contrast, a combi doesn’t require a storage tank of any kind, and that’s a huge space saver.

To summarise: if you regularly use 2 or more taps/showers at once, a combi may not meet your demand for hot water. So, if you’re in a property that needs high hot water output, you’ll want a system or heat only boiler, not a combi.

Ready to get your boiler installed? Get a fixed price on screen in 90 seconds using this anonymous, clickable form.

Heatable new boilers

Heat Only Boiler Installation Costs

You’ll see combi boiler deals from as little as £1,750, for supply and installation. But don’t expect to be pay that little for a heat only boiler. Compared to combis, conventional boilers require more materials and labour to be installed; this is why they cost more. 

For a start, there’s the cylinder; this part alone can cost hundreds of pounds, plus the labour to fit it. The same goes for the cold-water feed tank.

Usually, the cost of heat only installations relates to the size of the boiler and cylinder you require. Typical installation costs start at around £2,500.

Want to know exactly how much it will cost to install a heat only boiler on your property? You can use this boiler price calculator on Heatable and get an on-screen price within 2 minutes. And, thanks to their low overhead, Heatable offer Worcester boilers at incredibly competitive prices.

What kW Heat Only Boiler and Cylinder Do You Need?

A 24kW boiler and a 150L tank are sufficient for a 2-bedroom property; if your home is larger, prepare to spend more on a higher-capacity boiler and a larger tank.

To get a handle on how much your installation may cost, we’ve created 2 guides here:

  1. Hot Water Cylinder Sizing
  2. Boiler Sizing

Note that these guides offer a ball park only. Properties vary (even when they’re the same size) in terms of their heating and hot water demand. And, the last thing you want is a boiler that’s too weak, or too powerful (i.e. inefficient) for your home.

Any Gas Safe boiler fitter will be able to spec a boiler and cylinder that’s perfectly suited to your property. They can consider square footage, radiator BTU, number of rooms, how many taps and showers there are, and beyond.

If you want to get an accurate heat only boiler size estimate, you can also use this clickable form from Heatable.

What’s Next?

Thanks for reading our 10-minute review of heat only boilers.

We regularly post up reviews, guides and advice on heating, plumbing and bathrooms. Bookmark our blog and pop back soon.

Or, if you have a question, leave a comment below and we’ll get back to you as soon as possible.



Avoid Expensive Breakdown Costs
Boiler Replacement Promise: If it's under 7 years old and we can’t repair it, we’ll replace it.
Try YourRepair. From £9/mo
All plans include: annual boiler service, all parts and labour, unlimited support and 24hr helpline.

    Leave a comment

    Your email address will not be published. Required fields are marked *


    Fix things and tutorials

    Get a Boiler on Finance

    The best pay monthly packages available

    Read guide
    Heatable Boiler Replacement

    Want a new boiler from HEATABLE?

    Read guide
    WarmZilla Boiler Replacement

    Want a new boiler from WARMZILLA?

    Read guide
    Boiler Installation Costs

    Confused about new boilers and their costs?

    Read guide