Ball valve for central heating
Updated: 23 October 2026
You want to isolate a heating circuit, and a cheap lever looks as if it will do. A ball valve for central heating, on a primary, has to be full bore and fully open once the system is running, and the refill must not have a path into the mains. A half-open ball is not a balancing valve. General checks are on the [ball valve buying guide](/hub/diy-supplies/ball-valve/sub/ball-valve-buying-guide). The seven listings are in the [ball valve comparison](/hub/diy-supplies/ball-valve), captured on 19 October 2026. If you buy through our links, we may earn a commission at no extra cost to you.
You want to isolate a heating circuit, and a cheap lever looks as if it will do.
You want to isolate a heating circuit, and a cheap lever looks as if it will do. A ball valve for central heating, on a primary, has to be full bore and fully open once the system is running, and the refill must not have a path into the mains. A half-open ball is not a balancing valve. General checks are on the ball valve buying guide. The seven listings are in the ball valve comparison, captured on 19 October 2026. If you buy through our links, we may earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Port | Nominal size | Ends | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Bächlein Bächlein 3/4 inch female brass | Full bore | 3/4 inch | Female to female | 7.5 | about £13.95 | View offer |
| Alternative |  JIVTO JIVTO 1 inch BSP male to female | Full port | 1 inch | Male to female | 6.3 | about £15.48 | View offer |
| Best value |  JIVTO JIVTO 1/2 inch BSP full port | Full port | 1/2 inch | Female to female | 6.4 | about £9.98 | View offer |
On this page
Why the bore matters on heating
On a heating primary, trade notes including APM's guide want the hole through the ball as open as the pipe. Standard port is a restriction you leave in all season. In this set that is the JIVTO at about £8.68.
Full port or full bore is claimed on the JIVTO at about £9.98, the 1 inch JIVTO, the Gugxiom with no reviews, and the Bächlein 3/4 inch title, which does not print BSP. A ball valve is a poor lockshield. Albion says fully open or fully closed, because throttling damages the seats. That metal choice is on brass or stainless steel ball valve.
Ends you actually have
Nothing in this set is a 15 mm or 22 mm compression valve. Those sizes line up with 1/2 inch and 3/4 inch BSP only as a screwed equivalent. You still need a male thread into a female body.
The full-port 1/2 inch JIVTO is the candidate when both sides are 1/2 inch female BSP. Eighteen reviews disagree about the ball, so look through the port. The 1 inch male-to-female valve has a UK report of a drip when shut. The 2 inch Gugxiom belongs on a house primary only if you have measured DN50.
Pressure and temperature claims
A house circuit is not a 1,000 psi system. APM's rule of thumb is about 1.0 to 2.5 bar, and the boiler booklet overrides it. Seller figures of 1,000 psi or 30 bar were not tested here. Do not borrow PN16 for these ASINs.
Heated primary water is fluid category 2 in Schedule 1 of the Water Supply (Water Fittings) Regulations 1999. It must not return to the wholesome supply. Refill through the maker's filling loop, then put the loop back. If you cannot see the refill method, use a heating engineer.
The gas cock is not this job
The lever on the gas pipe is not this isolator. The Gas Safety (Installation and Use) Regulations 1998 require a Gas Safe registered engineer for a domestic boiler. Regulation 9 is the emergency control. A title that lists gas does not move that cock into DIY. If you smell gas, call the number on the meter. Keep every full-bore claim off the gas train.
What to leave open
If the valve is on a primary that should flow freely, choose a listing that says full port or full bore and match the male thread you measured. Leave it in line with the pipe while the pump runs. Refill to the cold pressure in the boiler booklet, through the filling loop, so heated water cannot return to the mains. If the lever you are looking at is on the gas pipe, it is not this purchase.
Common questions
Do I need full bore on the flow and return?
Yes, if the valve isolates a primary that should flow freely when open. A reduced bore is a restriction. The about £8.68 JIVTO is the standard-port listing to leave for that duty. The other full-bore claims still have to match the thread.
Can I balance a radiator with a ball valve?
No. Balancing needs a partly open valve, and these seats are not meant to work that way. Use the lockshield. Leave the ball valve in line with the pipe or across it. A lever at an angle can damage the seat, after which the valve may not shut.
Is 1/2 inch BSP the same as 15 mm on a heating pipe?
They are a practical pair when you choose a screwed joint for 15 mm copper, just as 3/4 inch BSP pairs with 22 mm. They are not the same end. A compression isolator has an olive. You need a male BSP adaptor before a female valve here can sit on that copper.
Will a 1,000 psi valve cope with heating pressure?
A house circuit is usually a low pressure. About 1.0 to 2.5 bar is a rule of thumb, and the boiler booklet overrides it. One thousand psi is a seller figure of about 69 bar, not a test. Use the cold-fill figure the maker prints.
Which listing is the right end for a boiler tapping?
Only the listing that matches the male thread. A 22 mm compression valve is not in this set. A 1/2 inch female BSP full-port JIVTO matches a 1/2 inch male nipple, not an olive. If the tapping is the gas cock, it is not this purchase.
Is the gas cock the same part?
No. The gas cock is on the gas supply. Isolating the heating water is a different pipe. Do not tape or replace that cock. The work belongs to a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations 1998. If you meant to drain the radiators, find the water isolators and leave the gas lever where it is.
What pressure do I refill to?
Use the cold-fill pressure in the boiler instructions. About 1.0 to 2.5 bar is only a rule of thumb when the booklet is missing. Refill through the filling loop so heated water cannot return to the mains, then put the loop back. Do not leave a ball valve cracked open on a hose.
Related pages
Sources
Public UK sources and the amazon.co.uk listings compared on this page. Shelf figures captured 19 October 2026.
- Water Supply (Water Fittings) Regulations 1999 (retrieved 19.10.2026)
- GOV.UK water fittings guidance (retrieved 19.10.2026)
- Water Regs UK, Schedule 2 paragraph 3 (retrieved 19.10.2026)
- WRAS directory guide (retrieved 19.10.2026)
- Gas Safety (Installation and Use) Regulations 1998 (retrieved 19.10.2026)
- HSE domestic gas FAQs (retrieved 19.10.2026)
- EN 13828:2025 (retrieved 19.10.2026)
- Albion Valves ball valve IOM (retrieved 19.10.2026)