Lukewarm water from brand new Valliant Eco boiler

[mumtorobbie]

We had a brand new Valliant Eco Tech Plus combi boiler fitted last year. All was fine until a few months ago when I turned all the rads off but left the bathroom one on (to dry our towels).

Since then, we've had very inconsistent hot water. I love, love, love hot baths but some nights the water is barely hot enough to wallow. I've since turned all the rads back on but just have the thermostat turned right down.

Valliant have come out three times and they say this is just how combi boilers work but this has to be crap surely?

If we turn the hot water right up to 60, it's bloody scalding when it comes out of the shower for some reason.

I wish we'd stuck with a boiler with a hot water tank in the loft to be honest.

it may be lukewarm from the hot bath tap, but what about from the hot basin tap?

the radiators are irrelevant. This is summer. Leave them off.

60C is normal for a boiler, and the most economical temperature. Your shower should have a temperature control knob to mix hot and cold, so there is no need for it to be scalding unless it is faulty or has been incorrectly piped.

Even at 60 the water is lukewarm and that's from the barh and downstairs taps.

it may be lukewarm from the hot bath tap, but what about from the hot basin tap?

It's lukewarm from every tap in the house but.....I've noticed that after the shower has been on the water is very hot so I guess there's a link somewhere.

I don't think there's anything wrong with the boiler in all honesty but it's bloody frustrating. Might have to call someone out to look at it.

it would be interesting to know how many litres per minute come out of the various taps, and what the temperature in degrees C is of the water.

The flow (LPM) of water will affect the temperature. It has to be high enough to trigger the flow switch in the boiler, but not so high that the boiler does not have enough power to get it hot.

I don't know if your model of combi boiler has a small cylinder inside of pre-heated water, which is intended to increase your availability of hot water. If it does, and it is turned off, then it will be adding cold water to the flow instead.

It may be relevant that if you have mixer taps, especially those with ceramic disks and joysticks, that the cold water can fotce its way into the hot pipes. Single taps are much less troublesome.

There's a comfort on and off mode - having it turned off and on makes no difference whatsoever.

As for the flow, no idea but I can certainly have a look when I get home.

Both basins (up and down) have a mixer tap but the bath taps are single.

I'm determined to get to the bottom of this. I really appreciate your help Piglet!

aha

"come complete with Vaillant's 'AquaComfort' system. This incorporates a warmstart facility, providing instantaneous hot water delivery and a controlling system to ensure a constant hot water temperature"

so I reckon you need to have it "on" and the boiler stat turned up tp 60C or whatever the instructon recommend, possibly higher.

Combis are usually good for showers, not so good for filing baths.

Really, if it is new, the installer should be dealing with these queries.

I am not a fan of combis myself, except in small single-occupancy homes. If you have the money, and a good incoming flow from the watermain, I prefer a Megaflo or similar pressurised cylinder, which can be used with a combi.

Ahh, right so if I turn the comfort mode onto on, that might help.

Right, I'll give it a go and report back.

And then I'll have to get someone to come and look at the shower to see why we're not getting any cold water!!

Thanks piglet.