Microbore balancing

[bilco_21]

Hi guys,
After a few days off hopefully our system is roughly balanced and somewhere near where it should be. Just a couple of questions if anyone can help. I balanced the system to around 10'C as stated in the boiler installation manual in order to get this figure i had to cut the lockshields on the upstairs rads to 1/2 to 1 turn open (3 turns is fully open) although the rads are quite small (600x400) and the rads downstairs are roughly 2 1/2 turns open. This gives me 70 flow 60 return with all the full heating circuit fully open. When the TRV's start close / closed i get about a 15'C in flow and return. The bypass set to 3 and pump speed 2. i just wanted to make sure that im not cutting the water flow to much as i know the 10mm plastic microbore is very restrictive to water flow and being a fairly low water content system, cutting the rads right down i don't want to cause any damage to the boiler or efficiency.

 

[Deleted member 25704]

Since the advent of combi boilers and trvs, and it has to be assumed that the boiler is of this type, balancing has been less important.

The key aspect of balancing on micro-bore systems was always more associated with the indirect hot water cylinder. I have improved countless systems performances by the locking down of the hot water circuit (notes these are 28mm and provide a short-circuit for the flow).

Other characteristics of micro-bore are need for auto bypass, which has been mentioned, as opposed to a manual by-pass, which was often the way it was done in the past (unless using a vcw vaillant, when auto-bypass was built in). In addition, a high head pump (6m head) was required.

System performance can considerably be improved by adding inhibitors, to a level of over-dose - 3 litres or more (but care must be taken if some boiler manufacturers specify otherwise e.g. vcw vaillants).

I have used inhibitors in the past like this, because it reduces friction, increases velocity of liquid flowing in system, which compensates for undersized pipework, sludge, blockages, faulty valves etc.

In these hard times, I suggest selling this as an upgrade to systems when you service the boiler - ask the customer if they want to improve the 'efficiency' of the system - its says it on the inhibitor bottle.

Boiler service + added inhibitor = reduction in system noise, efficiency, and better circulation and perhaps even a reduced risk of further electrolytic corrosion (however, I accept that in Germany they don't favour inhibitors, but they don't have heating systems, installed by amateurs like we do).

 

[DirksPlumbing]

(however, I accept that in Germany they don't favour inhibitors, but they don't have heating systems, installed by amateurs like we do).

You can not touch a system there unless supervised or trained sufficiently and you can not buy HEP2O and the likes there too. Any pipe suitable for heating systems will be of metal or comprise metal as in MLCP. PB, PE(X)x, PP, ABS, PVC(C) and what not are not to be used for CH systems.

There are literally no open vented systems. Except of a few remaining ones from the old days.

Inhibitor does get considered as not required as there should be no excessive oxygen intake.
I know systems in excess of 20 years which never have seen a flush or inhibitor and there is literally no sludge in them.

The mixing of different metals is only allowed if these are compatible. Pipe routing has strict regulations as much as the need for pipe sizing. You get away without but if something goes wrong you can wave bye bye to your expected payment in so far you have not made suitable measurements to ensure full functionallity and performance and can proof it (via calculation for example, loop closed).
Should there be unnecessary repairs, guess who will do them for free.
And if you thought of just bouncing your business to escape that then you can wave your 25k Euro bye bye you had to grant before being able to set your company up.

It has not so much to do with being amateurs. It is more a chain of liabilities that starts at the manufacturers (actually before already at normative body). And it has to do with continuous research and updating regulations independent of the manufacturers. And the options of developing yourself. A basic qualification is an equivalent to N(S)VQ3.
You can not opt for courses. You either do them all or you do not get qualified. The only option you have is your first year of training which will cover metal basics independent of your chosen subject. So you could swap for any other metal related training after that year with no wasted time. But after being fully qualified you can then make your way up to either a trade master degree or a technician degree which will be another 2-4 years of (expensive) study. If you then still are searching for more knowledge/qualification then the Uni with a matter related subject would be your next choice. All that is supported and enabled by a strong trade body that is not fractured in this and that and another independent one.