Simon, don't be surprised by the attitude of some of the forum regulars, it's nothing unusual although almost always totally unnecessary. Although some of what you've said is wrong, I don't see how or why it should have offended anybody.
I've been on enough forums for long enough to know that. I do try to avoid being rude to people though.
As to having got things wrong, I would be genuinely interested in specifics (if expressed constructively) - that is the route to improved knowledge.
So, what does the advice say about balancing ? Well one step is turning down the pump to set the flow in the "slowest" rad in the system. But this is a crappy combi - so you can't do that without affecting the DHW as well.
Sounds to be like you have something against combi boilers, although they work just fine when installed properly and sized according to the DHW and, to a lesser extent, CH demands. The pump may automatically modulate the flow rate, or there may be some adjustment possible. For example, you can select from two flow rates on some Viessman boilers through the front panel controls as detailed in the manual.
Newer ones are getting better - but you cannot get away from the fundamental problems they have. Unless they fire up (wastefully, as this BG one has the option of doing) periodically then there's a delay getting hot water. There is no way to size a combi correctly for both decent DHW capacity (needs big boiler) and efficient heating (needs smaller boiler, in general and they are improving with greater modulating ranges). And the biggy, it's a pain
when they break down and leave you with no heating or hot water. it's an even greater pain when they do it during the coldest spell for a while, and it takes several visits (and waits for spares) before it's fixed. With a hot water cylinder you have an immersion heater for the DHW, and fan heaters/gas fire can keep the rooms warm (or not too cold). A thermal store or heat bank can keep the hot water AND heating going on electric (though capacity will be restricted).
Every house I've lived in, for my whole life, has had a hot water cylinder (as it happens, all the traditional open vented type) - being used to that, I personally don't find the multiple compromises of a combi acceptable.
So yes, you may just get the impression I have something against combi boilers
I definitely have something against that significant proportion of people who treat combis as the best thing since sliced bread and refuse to accept that anyone could have anything against them.
But here's the special features of this system. It's 22mm from the boiler up into the upstairs floor, and it arrives at the rads as 10mm.
Nothing wrong with that, similar systems are still very common on new builds, and work just fine if the pipework is kept clean.
Agreed, nothing wrong with that, sorry if I gave that impression. It's the next bit ...
Clearly the small front room upstairs is fed from two pipes which are touching and not lagged - the flow temp is a full 15˚ less than some other rads!
Perhaps the radiator isn't receiving sufficient flow? The two pipes touching probably wouldn't result in such a large reduction in flow temperature, and the pipework run would have to be quite long for such a drop to have occurred due to lack of pipe insulation.
Based on heat output and temperature drop, I reckon there's adequate flow. I suspect that the two pipes are clipped together - so the flow and return are exchanging heat - the cooler return cools the flow, dropping the rad temp, and of course by the time the return gets back to the main pipe it's been reheated in the process of cooling the flow.
The two small rads in the downstairs dining area show the same symptoms - the pipes for those are visible behind the kitchen cabinets, and yes they've been run together, touching (even clipped together at one point), with no lagging. The rads get uniformly warm (and again the heat output and temperature drop indicate sufficient flow) - but the flow temp is 20˚ lower than what comes out of the boiler even after a couple of hours.
The living room downstairs has pipes dropped from upstairs - buried direct in the plaster down the wall. Lockshield fully open and it's still giving 9˚ drop, while the back bedroom is barely acceptable for noise at only 5˚. And the surface of the plaster is above 50˚ where the pipes are buried.
Again, nothing wrong with pipework below plastic, and far neater than having it on the surface. However, it's best put inside some form of containment such as conduit if buried in a solid wall, or insulated in some way to prevent heat loss into the wall if it's external.
I assume you meant to write "below plaster", it's the sort of thing I do, think one word, write another
Yeah, it's not the end of the world.
I guess I'll just have to save up and get a thermal store fitted like I've done in the flat - fully TRV'd system (fully modulating pump), and above all no combi
Needless to say, the house if built to maximise difficulty of altering anything like this
Your money might be better spent in getting a
decent heating engineer to investigate the problems with the existing system. There probably isn't all that much wrong with it, and if the boiler is in reasonable condition then it wouldn't be the end of the world if you had the system repiped in 15mm. Not that 10mm shouldn't work.
I think some fairly simple work would make a big difference - but that means getting at the pipework. Fitted carpets, and large sheets of chipboard flooring make access difficult without significant (more than I can afford time wise at the moment) work to reinstate. it still wouldn't get round the problem that this boiler isn't really suitable for the application - at least if you want it to perform as a condensing boiler is supposed to. Hydraulically, the easiest option would be a bypass (as onlyfitidealboilers suggested) - but that does nothing for efficiency.
Well I have a list of things I want/need to do. Sorting this out properly is on it - as time and money permits.
