CombiSave

[Scott]

Is anyone familiar with CombiSave? My boiler is fitted with this device and it does not seem to be working. The heating engineers who installed it are not providing much in the way of assistance. The servicing engineer didn't know what it was. The owner says it sounds like it's not working anymore and I need to decide whether to get a new one.

I understand this device is supposed to reduce the flow of water until the water reaches its intended temperature. There seems no evidence of any change in the flow. The boiler has an 'Eco' setting and a 'Pre-heat' setting (now set at 'Pre-heat'). Does the CombiSave work when 'Pre-heat' is on? Is it worth having at all or just a gimmick? Should it be removed if it is no longer working?

Thanks for any help. All I am getting from the installer is contradictory emails.

[alan_m]

This amazon listing claims a saving of up to £250 per year!

This guy with one fitted suggest more £25/annum but then his water saving figure may be suspect.

[John Rumm]

It sounds like it is supposed to throttle the flow rate water through it when it is cold, then de-restrict it once the water temperature rises.

The pre-heat may mean that it sees hot water almost instantly (which is the whole point of the pre-heat after all!)

Can't imagine it will do much - and nothing that could not be achieved by turning a tap on slowly at first. On taps with a long pipe run, you are still going to draw off a large amount of cold water anyway, and one boilers that need a fairly substantial flow to trigger DHW production it might even stop it working altogether.

[Fredxx]

I have one and apart from one hiccup it works as expected.

If it has always worked like this it wasn't setup properly. The CombiSave works on temperature only. It should allow a bleed flow to fire the boiler and then open (fully) once a temperature has been reached.

There should be no effect on the boiler if it's been fitted close to the boiler. The pre-heat does sort of nullify the effect of the CombiSave, and if the pipe surrounding th device is warm/hot then you will get immediate fast flow. Turning off the pre-heat might save you more cash than any normal saving of water!

They can be adjusted for minimum flow with the small visible adjuster and the opening temperature can be adjusted by removing the label.

Mine must have got jammed, so removed and dismantled it. It's been working well since and it's useful to tell you when to expect hot water, especially for a (power) shower where I hate the tray filling with cold water before I enter the shower.

As others say, I'm not convinced the saving of water is justified in terms of cost, but the principle of saving water and having to put up with full flow of cold water is a bonus.

[Fredxx]

The minimum flow rate is adjustable for those boilers with an insensitive means of detecting flow. Mine uses a rotating vane with a hall effect sensor and is fairly sensitive.