Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 20 replies
  • Subscribers 27 subscribers
  • Views 2456 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Do I need two mains supplies for boiler and wiring centre?

Former Community Member
Former Community Member

Good evening, Just like to say hello and that I am not a gas engineer or an electrician, but I would just like to understand what I need to ask for. I have a question about an old y-plan central heating installation dating back to 2000. I have an old Gloworm micron 50ff boiler situated in the consumer unit cupboard. However, it is connected to the wiring centre situated in the hot water cupboard 6 meters away via 3 wires, switched live, neutral and earth. I also have an old Grundfoss pump connected into the wiring centre that has only 4 wires, Blue, orange, brown-white, and grey, (I notice new pumps have 5 wires). The pump also has 3 settings using 40,65 & 95 watts. I also have 3 port mid-position valve, room stat, hot water stat and 2 channel programmer, (all from Danfoss heatshare pack).



 



Due to limited access in consumer unit cupboard I am limited to fitting either a Worcester greenstar ri series boiler or a Baxi ecoblue advance. Looking at the wiring diagrams, with my limited understanding, does fitting the Bosch require separate mains supplies in each cupboard, one for the boiler and one for the wiring centre and will the pump kill the boiler using an extra 5 watts as the worcester boiler is rated at 90 watts, and could I still use it with only 4 wires or would I need a new 5 wire pump too.



 



Or would it be better to go for what seems to be the simpler option of the Baxi as it requires no pump overrun or permanent live and looks as though it is fed with just live, neutral and earth from the wiring centre as I have now.



 



Sorry about the long question, and many thanks in advance. Simon.


Parents
  • 0
    Today I am going to replace a faulty programmable room thermostat/water timer with a remote sensor.  The clever bit of the thermostat is under the wall mounted boiler adjacent to a SFCU which controls the power to the thermostat and the thermostat had got a bit wet. 


    On my first visit having determined it was broke, with the SFCU turned off and the clever bit in my hand, I was pondering how to give him hot water until I could get a new one. Then I realised the boiler had just fired up. Then I am told there is another clever thermostat on the first floor and a heat store for the water which are both still working. This answered the question why one of the terminals on the thermostat backplate was live when there was no incoming power.


    So this installation has more than  one point of isolation and the most obvious SFCU by the boiler does not. I am going to stick a nice label on it in to warn any unsuspecting plumber or electrician. To misquote  from Monty Python "Always expect the unexpected"
Reply
  • 0
    Today I am going to replace a faulty programmable room thermostat/water timer with a remote sensor.  The clever bit of the thermostat is under the wall mounted boiler adjacent to a SFCU which controls the power to the thermostat and the thermostat had got a bit wet. 


    On my first visit having determined it was broke, with the SFCU turned off and the clever bit in my hand, I was pondering how to give him hot water until I could get a new one. Then I realised the boiler had just fired up. Then I am told there is another clever thermostat on the first floor and a heat store for the water which are both still working. This answered the question why one of the terminals on the thermostat backplate was live when there was no incoming power.


    So this installation has more than  one point of isolation and the most obvious SFCU by the boiler does not. I am going to stick a nice label on it in to warn any unsuspecting plumber or electrician. To misquote  from Monty Python "Always expect the unexpected"
Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines