Iboost+ hot water too hot!

ntc1945

Has solar panels installed last week and the iboost+ then made the hot water too hot to touch. Told the tank thermostat had failed. Replaced the element and stat and the water is still too hot, though not enough sun just now to tell how hot it could be. How can the iboost override the tank thermostat which is set at 60c? Have to keep turning it off. And ideas please?

JKenH

The IBoost can’t override the tank thermostat. Modern immersion heaters have two stats, one of which is a safety cut out, the other is adjustable. You may need to take a metal cover off then turn the thermostat down.

Edit: some more info here about adjusting the ‘stat.

https://www.diydata.com/problem/immersion/immersion_adjustment.php

It may be your old thermostat was on a timer and the IBoost is just sending power to the immersion heater for a longer period of time. If it is heating for longer there is more chance you will have circulation currents and more of the water in the tank will get heated.

QrizB

ntc1945 said:

Has solar panels installed last week and the iboost+ then made the hot water too hot to touch. Told the tank thermostat had failed. Replaced the element and stat and the water is still too hot, though not enough sun just now to tell how hot it could be. How can the iboost override the tank thermostat which is set at 60c? Have to keep turning it off. And ideas please?

The immersion heater is not connected to the tank thermostat, but as JKenH says it will (or should) have its own internal thermostat. If you switch off the power then remove the cover you'll see it. Usually it's something like this:

Turn the arrow to roughly the temperature you want, then fine-tune as necessary.

paul991

due  to some bad accidents all immersions should  have a temp stat and a safety cut out .it would be  wise to check yours has, it  should look like a small usually white pop up circle on the stat or on the heater base.if  yours has not  got this it would be worth  replacing your  stat with a new one that incorporates a safety cut out .one  bought within last ten  years should have one

paul991

reading what  you have have posted , 1 the element was ok and didn't need replacing.either the new stat is faulty or not wired in properly,2 you have another source of water heater <gas or second immersion.

paul991

if  you have  no luck ,with power off remove the lid of the immersion and  take a picture of  the wiring   

ntc1945

Thanks for the comments. I have had a brand new immersion element and thermostat installed now which doesn’t seem to have made much difference. The gas hot water comes on in the morning at 7until 9 . When solar kicks in it seems to keep heating up,the hot water and ignores the tank’s internal thermostat connected to the element. It should cut out at 60c however much Solar is being created but it seems not to. Water coming out was steaming and couldn’t put hand under it.

Hexane

Your immersion element is not in any way connected to, or controlled by, the 60C tank thermostat which turns the gas central heating on and off.

As in the picture that QrizB included, your immersion element will instead have a limited temperature control mounted in its top. Mine is set to 80C (as in that picture) and this is indeed too hot to put your hand under the water.

Installers who are fitting iBoost type products should be explaining this to their customers either before installation or at the time of installation.

There's no point setting your iBoost type product to only heat your water to 60C, if your gas boiler has already heated your water to 60C. We use mixer taps.

markin

If you do set it to 60c the gas will always beat it to heating it up so you would have to turn the gas off and risk ending up with cool water, You want it at least 70c and then fit a safety mixer valve, "Anti-Scald Valve" or safety mixer taps,  The searches on Wickes, B&Q/Screwfix have become useless so i cant find one to link to.

pegler PDF

https://www.pegleryorkshire.co.uk/MEDIA/Downloads/CC_004/70050873_Pegler_Thermostatic_Mixing_Valves.pdf

ntc1945

Thanks for responses but I still don’t understand why the stat attached internally to the tank doesn’t repel solar input when it reaches 60c. 

Verdigris

ntc1945 said:

Thanks for responses but I still don’t understand why the stat attached internally to the tank doesn’t repel solar input when it reaches 60c. 

Because it controls the gas boiler, which has nothing to do with your solar system.