Electronic TRV's 2012

[CHRISMU]

Edit for my post above

"Hello again Chris",


Thanks for your reply.


As You have a Baxi 105 HE Combination Boiler I can give you some `reassurance` regarding a couple of points:


This Combi Boiler has an integral `Automatic Bypass` which will allow the Pump Over-run to not be pumping against no circulation in the unlikely event that this were to occur.

Depending upon the circumstances regarding the Boiler Interlock this `Built In` Bypass would not really be capable of Heat Dissipation because there is simply not enough pipework to dissipate the Heat - but this should not cause any problems as usually there is always some circulation around the Heating System - unless all the TRV`s were closed at the same time - which could in theory happen.

Without checking I think that I remember the Baxi 105 HE has up to a 30 Minute Pump Over-run [?] and obviously this would mean that the Flow and Returns would have circulation for that period of time.


Obviously You already know that there is a Hot Water `Pre Heat` Facility on the Combi which will [if selected] cause the Boiler to Fire Up to Heat the small Hot Water store within the Combi - this would happen frequently - so that will also cause the Pump Over-run to operate frequently

I assume that You have a Copy of the User and Installation Instructions for the Baxi 105 HE - ? - some of the brief descriptions of operation might be useful to read to see the process / sequence of operation.


I cannot comment upon the Wiring for the Boiler Interlock - for two reasons:


Without seeing the exact wiring diagrams it would not be possible.

And also - since approximately 2005 it has been a requirement under `Part P` of the Building Regulations for Electrical Works to be carried out by a `Competent Person` - this means in law an Electrician who has the necessary Qualifications and is Registered with an Electrical Competent Persons Scheme - for example NICEIC - it would definitely be inappropriate for Me to advise on Electrical Wiring on this Forum or any other.


Up to 2005 I had previously been deemed as `Competent` in Essential Electrics and Electrical Installation for Mechanical Services having taken Training and Assessment in those - ACOPS.

I then completed `Training and Assessment` for `Defined Scope` [Heating and Gas Appliances] Part P and I Registered with an Electrical Competent Persons Scheme - this process was `Valid for 5 Years` [Re-register every Year] but as the costs are `prohibitive` for someone who is NOT trading as an Electrician I let this lapse in 2010.


Because of the Building Regulations in `Part P` and obviously the possible Dangers of carrying out Electrical Works / Testing etc. I feel that I am not able to give any Advice or Information about the Electrical Wiring of Heating Controls etc. on a Forum.

My Heating Systems are all wired up by a Fully Qualified and Registered Electrician - any Electrical Faults on New Boilers are obviously covered and dealt with by a Service Engineer from the Boiler Manufacturer - although I would be able to diagnose what component was at fault by various tests.


I hope that these comments are of some help Chris.


Regards,

Chris

"Hello again Chris".


Further to my message to You above - I need to submit an Edit to clarify something that I wrote:



EDIT FOR THIS PARAGRAPH ABOVE:


QUOTE:


Depending upon the circumstances regarding the Boiler Interlock this `Built In` Bypass would not really be capable of Heat Dissipation because there is simply not enough pipework to dissipate the Heat - but this should not cause any problems as usually there is always some circulation around the Heating System - unless all the TRV`s were closed at the same time - which could in theory happen.


END QUOTE


I should have written that with MOST Heating Systems connected to a Combination Boiler there would usually always be some circulation path in operation.

This situation can be different when there are Zones engineered into the system which use Electronic Zone Valves - depending upon how these zones are created and where the zone valves are installed there could be a situation where ALL circulation paths are closed - except for the Internal Automatic Bypass in the Combi Boiler.

Obviously this does not apply to your system Chris - but I have written this Edit because of other readers - including other Heating Engineers who sometimes take pleasure in contradicting `Fellow Professionals`.

That is NOT directed at the `Fellow Professional` who posted some useful information on this thread - neilhooper - My comment is prompted by experiences on other Forums.


Regards,


Chris