Nest thermostat and system boiler

ladymarmalade222

We have recently moved into a new property which has a fairly new boiler which I believe is a system boiler. It is an ideal logic which we have been told is crap and to replace as soon as we can. It heats the water separately to a smallish tank in the airing cupboard.

I have only ever been used to combi boilers coming from a 2 bed terraced but this house is over 3 floors and has bathroom, en suite and downstairs loo. We never use the showers at the same time or bath/shower at the same time. The old occupiers have also installed a large pump for the power showers which is the noisiest thing I have ever heard:rotfl: but I believe an anti vibration mat is the solution as it has been installed on wood.

Anyway I hated the old thermostat so decided to go with a nest which I love for the heating but I am finding it really glitchy for the hot water and 50% of the time I have luke warm/cold water even though it is being heated the same 2 x 1hrs every day.

Has anybody had any experience with installing a nest on a system boiler. I noticed the tank had a honeywell thermostat connected to it which I was told was no longer able to work now the nest was installed, is this the problem? The water when it does heat is also not as hot as it used to be.

Can anybody explain in plain english what is now happening as I understood my old system but this one is now baffling me.

Many thanks in advance

xxx

greenbee

I have a nest thermostat and a system boiler. For the hot water, the nest controls the timing in the hot water tank but not the temperature - that should still be set on the tank.

ladymarmalade222

greenbee wrote: »

I have a nest thermostat and a system boiler. For the hot water, the nest controls the timing in the hot water tank but not the temperature - that should still be set on the tank.

So the honeywell thermostat on the tank should still be working? I can hear the tank still filling up when i use the hot water but the water is not as hot and we are only getting the water heating 50% of the time. The installer mentioned the temperature is now controlled from the system boiler now and the thermostat connected to the hot water tank was redundant.

Also when i go into the settings on the nest itself there is not an option to change the water temperature which reading the nest site it says i should be able to do.

Thanks for your help.

Xx

Gloomendoom

If there is no temperature sensor feeding the tank/water temperature back to the Nest, how can it control the hot water temperature?

ladymarmalade222

This is what confused me but he did say it was no longer working.

I am getting hot water when i boost on the nest no problem but it seems to be the timed bit is not heating it up properly...hence why I am banging my head��

Thanks again

Xx

southcoastrgi

You can't change the hot water temp on your nest because your boiler isn't opentherm so will just turn on or off, the hot water temp is now controlled by the stat on the front of the boiler which is a bloody stupid idea because your cylinder is designed to get to 60d whereas you will want your heating around 75d

Robin9

Is 2 x 1hr really enough ?

Try running it on continuous - and see if you get enough then.

ladymarmalade222

Thanks everyone. So why do nest say it works with heating and hot water.

I am getting hot enough water now for a bath when I boost it. It just seems the program i used before with the honeywell of one hr in the morning for my partners shower and one hour at evening for my bath and sometimes a shower for my son is leaving it luke warm.

Surely leaving the boiler to continuously heat the water is gonna cost a fortune where as I am trying to cut my bills��

Xx

ladymarmalade222

Also we have a dishwasher so do not need to wash pots hence the 2x1hrs timings

Xx

southcoastrgi

The 3rd gen nest will control your hot water if your boiler is opentherm but yours isn't, you might have been better with a 2nd gen one which would have been cheaper to buy as well, when you do look at replacing your boiler I wouldn't look at WB as most of theirs aren't opentherm either (for what are supposed to be the best selling boilers they are way behind the best boilers around) I'd look at Intergas or the latest Atag's

JP1978

All Nest 3rd Gen does (and the others as far as I am aware) is to turn on or off the hot water. It does not decide its temperature. There will be a dial on the boiler to set the temperature - set that higher.

When that is higher, the central heating will also take less time to heat the house as the water its using is a higher temperature.