SimonD

Yup, it's a bit of a sh*t show. Do the meaurements I suggested so that we know flow and return temperature rise over time and can then assess differential within each circuit.

Yes, do the tests and then we have some data, otherwise it's all speculation. Right now we have either/and: - a problem caused due a flow problem somewhere within the system; - a simple issue of short-cycling due to low volume of the ufh; The system bypass isn't really relevant as that's just there to prevent a no flow situation through the boiler when trvs are fitted to all rads. Some boiler manufacturers specify a minimum bypass length (e.g. Worcester Bosch say 3m on some models) so that there's a minimum heat loss through the circuit - but that's not relevant right now, nor is it relevant to the boiler short cycling as @JohnMo has said. Other questions: Does your boiler make any funny noises just before it turns itself off? Have any of the engineers suggesting a new boiler even mentioned a heat loss calc to correctly size the new unit and mentioned selecting a boiler with good modulation ratio? Have any of these engineers mentioned that it's the controllers that govern boiler modulation rather than the boiler itself? E.g. the Vaillant VRC 400 weather compensating control for Ecotec boilers that adjusts flow temperatures according to a heat curve and heat demand?

I think you can probably ignore the hot water system for now and just run the heating system so you have all rads plus ufh, then all rads no ufh and then no rads and just ufh basically so you're monitoring each zone. That should give you a reasonable picture to start with. Every 5 min or so should be fine. You want to be taking these readings until you see the boiler cycling. It's a bit tedious I know...

First do the investigations to get the data that supports the decisions. You can get the flow and return temperatures from your boiler yourself - d.40 for flow, d.41 for return temp. Run your system fully open and log readings over a period of time, then methodically close parts of it down while taking recordings over time, including the ufh only.

The op says about engineer looking at the ufh: "he was not 100% sure where the issue lay. He said there could be a blockage somewhere and/or the heat exchanger could be partially blocked." In any case, the flow rates need to be checked and confirmed and in relation to the temperature drop across the system - is the boiler cycling because there is too much temperature differential still (and corresponding low flow rate) or because the temperature differential is too small? I'd want to know this information. In each case a buffer cylinder could be of benefit, but it may need to be implemented differently is each instance. In one it may be necessary to differentiate flow rates between heat source and heat emitter where they need to be different, and/or to buffer the excess output from heat source that can't modulate down enough for the current heat loss.

Plastic - layflat polybutylene myself. Some copper in places. I prefer to use polyplumb pushfit now over both Hep20 and Speedfit.

First you have to diagnose the cause of the error message and that's only by a process of elimination. A competent heating engineer should be able to do this, but it does take some time. Then, if indeed a flow problem has been found somewhere on the system then this gets rectified accordingly. Sometimes it can be caused by a faulty fitting, sometimes due to crap in the system. Again, it's a process of elimination. For me the best tool I have for this is an infrared camera that immediately picks up temperature differentials in the system which will helps to zone in on where the problem lies. You need a cogent explanation of what is going on which means a proper assessment of the functioning of the whole system. Only then do you proceed with spending money on new bits.

High difference between flow and return temperatures is usually caused by a blockage of flow in your system somewhere, not the boiler - the boiler is shutting off due to the low flow. Short-cycling is caused when you don't have enough temperature difference between the flow and return but the flow is sufficient through the boiler. They are different problems that need to be separated. Get the flow problem understood and resolved first before spending money on a new boiler or a low loss header. Nowdays a heating engineer should really be doing a heat loss calculation to appropriately size the boiler as part of the replacement job.

You can but there are rules. Did the import documentation include your VAT registration number? I.e. did the supplier have your VAT reg number when completing the order and shipping info? If not, then you probably won't be able to claim. If it's on there, then you should be able to do it. My recent imports have all asked for VAT number at the time of ordering. HMRC rules here: https://www.gov.uk/guidance/check-when-you-can-account-for-import-vat-on-your-vat-return

Somewhere I have a paper on this, looking at cycling/running time intervals and determining the overallimpact on efficiency. It was certainly not a binary answer. My initial search can't find the paper so I don't know whether I actually saved it, unfortunately.

I buy from Rejs Ltd - https://www.rejsltd.co.uk/drawer-runners they sell some heavy duty runners up to 100kg.

I've used heat engineer in one project and won't use again. The calcs were fine but I put in the data for a completely new installation I was quoting for. Left it a week or two while the customer was mulling it all over and when i went back in to update it all, my whole project had dissappeared from my dashboard and couldn't retrieve it anywhere. Plus I had numerous problems using it with Safari so had to install Chrome. I've just created my own calculator now.

Design and install myself including welding up the manifolds. Ironically, I've trained and become Gas Safe registered since doing it! Yes, pressure test. There are some fairly cheap pressure testers you can get off ebay for one off use.

IMHO the best place to start with system design is with the industry manual: Domestic Heating Design Guide - Everything is in there with regards to heat loss calculation (although the BH community tend to use the calculator designed by Jeremy - you'll find a link to it on the forum), pipe sizing and emitter sizing. For manifolds specifically, I've found scant info on the design but made my own using the the above linked design guide to size all the primary and secondary pipework sizing. Works all fine. My manifolds were copper, soldered with full bore level valves on flow and return to each rad. As already mentioned, you'll need 2 zones but that's pretty simple in the grand scheme of things. One thing not covered in the design guide however is priority hot water setup (sometimes referred to as X-plan) with the heating system which is more efficient than your typical S or Y plan. Select your boiler on its ability to support different DHW and CH temp outputs, its modulation and likewise compatible controls that will modulate boiler output.

Often frowned upon by the old school boys, but mightily handy when you're in a tight spot is the good old friend, Macalpine and his flexible waste connectors. Maybe can help in this instance: https://mcalpineplumbing.com/plastic-chrome-fittings/flexible-fittings-non-return-valves/flexcon5c-flexible-fitting-universal-x-plain-spigot

Thanks all, that was my first port of call. Unfortunately I'm finding the same difficulty getting hold of PAR in the dimensions I want. I've build the door openings for 32mm linings, assuming finished nonimal 27-28mm, but nobody locally stocks or supplies any 32 x in widths greater than 138mm so about 132mm finished. One merchant does list 32 x up to 225 but no stock. Other than that, I've got to go to 38mm so 32mm finished which means trimming the doors which have all been supplied pre finished. Oh, actually, I may have just found some with 32 x 150 so possibly okay for most walls. I just wonder whether this will work okay with shadow gap beads. Then need to find something for the walls with 140mm cls.

I wonder whether I've made a bit of a mistake in my planning. In the designs we've gone for metric doors and the bigger ones too. 826 x 2040 and some 926 x 2040. Fine for the doors eventually as I've found availability a problem for a while. Now I'm struggling with door liners - lots available off the shelf with trenched headers for the smaller doors and untrenched for imperial door widths, but few and far between for the metric liners. The other thing I've found is that the liners are often not wide enough to deal with the full width of my stud walls which use double plasterboard each side, so with stud, PB and skim, none of the standard dimensions work out. I'd like to use 32mm thick door liners, so finished size of ca. 27-28mm but unless I pay silly money - e.g. £80 per liner, it doesn't seem practical. My thoughts now are to getting some 25mm MR MDF ripped to size instead. Any other thoughts or suggestions? (other than plan better in the future 😁)

I just thought I'd add to this one as I just came across Robin Clevett's (from Skill Builder and his own Youtube channel) new hinge jig at https://www.robc.co.uk/shop/ Looks very neat as it doesn't use router bushings but a router cutter. No jig for the door lock yet mind you.

Have you done it yourself? I'd be interested to know any experience of the BCO process of this

I know it well, I'm in the trade too nowadays hence my reference to treating customers. You could very well be right on that.

I do wonder about that. My sister said the same thing, but the electrician dissappearing is mostly what's confounding me as I even did him a full day's work trenching as a favour when he was let down by a ground worker he'd employed.

No definitely none of that. I'm mostly running around doing my own stuff and out to work myself. I just leave them to it! Never clock watch just allow the progress to happen as it happens too and trust them to do what needs to be done.

So, after building most of the house entirely myself, I finally succumbed to getting some trades in to help finish things off. Main items were a chippie and electrician. I agreed start dates and scope of work with chippie, ordered all the interior doors and then the day before he was going to start he asked if he could reschedule for the following week. I said okay and then the follwing week he texted in sick and I haven't heard from him since. Next the sparky. He was coming in a day or two per week. Has done 1st fix downstairs ring main, kitchen and a few other things. Now needs to to ring for upstairs and then lighting circuits. I've paid him promptly and just let him get to doing the work. Now I haven'r heard from him in a few weeks and he hasn't returned my calls. I don't treat my customers in this way and am totally bemused. Am I doing something wrong and if so what could that be? I'm now starting to wonder if I need to do the electics myself and pay building control for sign off.....☹️

What often gets overlooked is the alternative and even more maligned approach: proper regulation. If the regulatory framework had been constructed and governed properly this crisis may well have been averted. It's not dissimilar to the financial meltdown and is only the beginning I fear as so many other companies are massively leveraged, many of which are inflation linked too.

Beautiful location. Strange as it may seem, take a look at Falu Red - an original paint from the copper mines in Falun Sweden. In several regions, it's the only colour you're allowed to use in rural settings and it strangely blends in very well. It also protect the timber in harsh conditions but lets it breathe. With Falu red you can use softwood. We've used locally grown Cedar for our current house due to planning (it's silvering very nicely) but I would definitely build a timber frame house finished board on board with Falu red one day - reminds me of my second home and upbringing. Here's a gallery: https://falurodfarg.com/inspiration/bildgalleri/