iboost+ immersion heater question

NoobSolar

My hot water tank (gledhill stainless) has two immersion heaters. Sparky has wired up my upper and lower immersions the wrong way round - lower to htwr1 and upper to htwr 2. This is contrary to the installation instructions, which say it is necessary for the top immersion heater to have priority. Is this going to be a problem? What will the effect of this be?

Meatballs

Its supposed to heat the top one first, to give you the top layer of stratified hot water that is immediately usable, then switch to the bottom one to heat the rest.

It will now heat the bottom one first, heating the whole tank and get no benefit from fast heating of the top to draw off.

Won't cause any real issues except that loss of benefit (I only have a bottom immersion anyway), but may as well ask them to swap it over.

JKenH

We have 2 hot water tanks each with 2 immersion heaters. Our IBoost is wired to the bottom heater in each tank and works just fine. As water heats up it rises and so there will be circulation currents within the tank. We do have separately controlled heaters at the top of the tanks but only ever use them when we have visitors. 

NoobSolar

Thanks both. I assume therefore, JKenH, you are diverting quite a bit of energy to your two tanks. It seems to me that this is only a concern if the tank is cold and I jolly well want to do the washing up quickly. Generally in the morning we have a bit of hot water left after our showers and so on. So I guess it is a case of asking him to swap them round but not as a matter of urgency - especially as we won't be generating much from our new 6kw array until it is warmer.