Replacing Honeywell ST7100 with Nest Thermostat

Today I finally got around to fitting my Nest 3rd gen thermostat, ran into a few issues with the wiring as I was under the assumption that it was clever enough to not need the wires to the common connections for the central heating and hot water if they were the same as the main live, which they were on my original Honeywell setup.

Turned out after wiring it all in that indeed, you do need to jumper connect from live to each of the commons, at least in my case. After figuring this out I think my system represents the Y plan setup in the diagrams.

n case someone else plans to replace a Honeywell ST7100 with a Nest thermostat you need to wire it as follows:

  • Any spare lives (I had two) into a connector strip and ignore
  • Main live goes to L on the nest
  • Neutral, I had three wires going into this so fed them into connector strip then a single wire from there to the N on the Nest
  • 8 on ST7100 goes to 6 on the Nest
  • 7 on ST7100 goes to 4 on the Nest
  • 5 on ST7100 goes to 3 on the Nest
  • Then the missing step I had, link L to 2 and 2 to 5

One thing I have discovered is that whilst the Honeywell seemed to give preference to hot water if both heating and hot water are requested, the Nest seems to give preference to heating. This lead to a lack of hot water on the first few days, but now I have just changed the schedule to be at times when the heating is not on.


New job, washing machine repair man

Washing machine in bits
Washing machine in bits

So after many MANY hours of hard work I managed to disassemble our washing machine, replace the bearings and put it all back together again. This made me immensely happy as for £30 and about 6 hours of my time I thought I had brought our washing machine back to life and saved us many pennies.

Unfortunately whilst everything seemed to work fine when it was doing its wash cycle, once it came to doing it’s spin it sounded VERY unhealthy and I ended up unplugging it.

Lesson learned that I am not a washing machine repair man and we ended up buying a new washing machine. On the plus side I found out a friend of my mum’s IS a washing repair man and so he is going to collect it and strip it down for any useful parts and recycle the rest, apparently replacing the bearings on an LG direct drive machine is not generally a DIY job and he was amazed I even attempted it.