No hot water from kitchen mixer tap in combi boiler setup!

sadmuso

Hi All,

Over the last couple of months our mixer tap in the kitchen has slowly been getting more unreliable for hot water and this week it's pretty much always cold. I just tried it again now and managed to get piping hot water for about 30 seconds but it just reverted back to cold again. The house in on combi boiler and I get hot water everywhere else, so I'm now trying to isolate the issue.

Does anyone here have any ideas? I presume it's something to do with the piping or the tap itself but don't know where to start. I'd like to do it myself but always get scared when water is involved!

I should probably also point out that I'm not getting a poor flow when it's turned to hot - it still seems to be flowing with the same pressure that it always has except now it's cold!

Many thanks

I_have_spoken

Mixer taps likely needs a new cartridge. Plenty of youtube vids showing how to change

Le_Kirk

When you open the tap does the demand light on the boiler illuminate? Does it stay on? What happens with other taps in the house?

MrBluesky_2

is your tap a single lever operated unit or 2 individual hot & cold taps ?

joshardy

I'm having the same problem. The demand light does not illuminate on the boiler. When I have both taps fully on, there is no noticeable increase in flow over having only a single tap fully on. Any ideas? It is a mixer tap with individual hot and cold taps.

Le_Kirk

Do you have good flow from hot taps in other parts of the property? If so, answer given in post #2

joshardy

Unfortunately the cartridge is not the issue - I've replaced both hot and cold and the fault remains. I plan to remove the tap and place a washing machine hose on the hot water feed to see if there is sufficient pressure there - this will hopefully tell me if the problem is with the mixer itself or there is fault somewhere else in the system. Is this a sensible next step or is there something else I can do without disconnecting the feed from the tap?

Le_Kirk

What about other hot taps in the house? If they don't call for hot water, i.e. the demand light does not come on, the problem is likely the flow switch. If the demand light does come on with other taps, the issue is with the kitchen tap.

joshardy

Le Kirk - thanks for you help so far. All other taps in the house are fine - hot water, and pressure, everywhere. I suspected it was the tap but didn't want to go and spend £75 on a replacement if it's something simple within the tap I can sort out!

Le_Kirk

Seems weird if you have replaced the cartridges and it's still an issue. Were they the correct type for the pressure and correct (i.e. same as the old ones) direction of opening? You said mixer tap in your first post, how is the mixing done? Just by turning on each of the hot and cold taps until you get the required temperature or is there a separate mixer valve? Presumably you have tried just turning on the hot and leaving the cold closed? Your idea of connecting a washing machine hose to check the flow seems a sensible idea.

joshardy

Le_Kirk - I feel like a bit of a fool but it seems the 'aerator' or whatever it was called was blocked up - I took it out and everything is sorted - you were right - it was the tap but i've sorted it out now. Thanks again for your suggestions.