Hot and Cold Mixer Taps

Where a Mixer Tap Belongs

At the basin, only with a heater. A basin mixer tap needs hot water piped to the basin from a storage or multipoint heater. That is not the usual Malaysian set-up, where the basin runs cold, so confirm the plumbing before choosing a mixer over a basin tap. Tall mixers suit counter-top bowls, standard ones suit inset basins.

At the shower, concealed or exposed. A concealed shower mixer sits inside the wall with a plate and handle showing, and often a diverter that switches between rain head, hand shower and bath spout. An exposed mixer sits on the wall face, either alone or as part of a shower set. Both need hot and cold at the shower point.

In the kitchen, with a pull-out spray. A pillar-mounted kitchen mixer with a pull-out hose rinses the sink and fills a pot on the counter. It needs a hot feed under the sink, usually a small storage heater. The kitchen faucets category has the cold-only versions as well.

Single lever, ceramic cartridge. Most mixers today are single-lever: lift for flow, turn for temperature, with a ceramic cartridge inside. Hot is on the left by convention. Two-handle mixers still exist and are easier to service, but the single lever is the one most people want.

Heater, Pressure and Fitting

Instant heaters do not feed mixers. An instant heater heats water as it passes and has its own outlet and hand shower. A mixer needs a hot feed piped from a storage heater or a multipoint heater serving several outlets. If the bathroom has an instant heater, the shower is already handled and a mixer is the wrong part.

Balance the two pressures. A mixer works best when hot and cold arrive at similar pressure. A pumped cold supply and a gravity-fed hot tank push cold across into the hot side, and the tap runs lukewarm however far you turn it. Your plumber can tell you whether the two feeds match.

Concealed mixers are a first-fix decision. The valve body goes into the wall at the right depth for the finished tile face, before plastering, and cannot be changed later without opening the wall. Exposed mixers, bib taps and shower taps can be swapped at any time.

Hard water and the cartridge. Scale stiffens a ceramic cartridge over years. A mixer whose cartridge can be replaced from the front, without removing the tap, saves a plumber's visit later. Ask before buying.

Isolate both feeds. An angle valve on the hot and one on the cold, at every mixer, so the cartridge can be changed with the house still running. Hoses on the hot side should be rated for hot water; an ordinary cold hose softens.