JohnMo

But how deep? Replace seals, either replace with new seals from manufacturer or replacements from Screwfix etc Don't you will cause way more issues with damp Good guess will be drafts, you really need to understand where they come from and fix them, most is more time than cost. Draw curtains at night. Also how do you operate your heating system, tell us time schedules, room thermostats or TRV - as much info as you can. At lot of uncomfort comes from the way people operate the heating. What boiler do you have system (with cylinder) or combi (no cylinder)?

Sorry not exactly new - European manufactures have been designing boiler for low and slow weather compensated, room compensated heating systems for decades. UK manufactures offer drummed down technically poor boilers, manufacturing and installing, with the basis of design being S and Y plan heating systems, they should have been banned the day condensing boilers were mandated, a few decades ago.

Im running 300mm spacing without issue, wouldn’t fret too much. I have 1x 100m pipe doing main bathroom, then it does hallway by front door and then kitchen diner

I'm a bit confused. Is this a new build a renovation or something else? A drawing would help showing what was planned and what you got. What is the wall construction? The doors and windows have to straddle wall insulation, if it's doing that, the detailing on the floor is rubbish. If windows and door are not a straddling the wall insulation, get the installer back to fit them correctly. Does you floor match what the walls are doing with respect the cavity?, if so the door looks from the photo to straddle the cavity. Was that work agreed to was that shown on a drawing they worked to etc - if shown on drawings and they agreed it was in there scope, get them back to do the job correctly.

Have a look for a Heat Geek installer in your area. They have been trained properly on low temperature heating systems etc. if you go on to the heat geek website there's a page for finding local installers

It is easy you don't need anything fancy. Start of trial take gas meter reading, getting a book or your phone, sit by the boiler for an hour and see what it's doing. Measure gas usage over 24 hrs. Note down outside temperature. If you have a smart meter, it will tell you usage every 30 mins anyway. Start trial exactly as you are set up now. Run first phase over a week to get some decent readings. If boiler is cycling a lot that is the first thing to fix. Time the whole ground floor to heat at the same time as the garden room UFH at a normal temperature (20 Deg for example). Again monitor over a week what happens. While you are doing the trial, test with your hand a radiator when room is up to temp are your trvs closing off the radiator or does it just run a little cooler. So basically are your b.vakves on off or modulating? Then look at the numbers, are you using more or less gas is the boiler cycling as much etc. Then start to reduce boiler flow temperature again see what happens in baby steps. I spent months understanding what my boiler was doing, went from thermostat micro managed room climates, to a fully open system, reducing gas consumption by over 50%, mostly due to boiler short cycling.

A big Viessmann combi A Vitodens 200-W has a 17:1 turndown, so you could install a 30+kW for great DHW performance and still it would tick away down to below 2kW when it's mild. Set the boiler to run WC mode and it would fire up alter flow temp automatically and boiler would run for long periods at best efficiency. Comes with up to 10 years warranty Atag make a good boiler, turndown isn't as good as Viessmann, but a solid machine.

Is this a new build or retrofit? What's below the UFH pipes?

So your boiler has a minimum output of a out 10kW, which is pretty huge. So you really need most of your radiators on, while you try to run the UFH. Bringing down your flow temp will help, as it will slow down the system and reduce radiator output, so thermostats cycle less. Tell us more about what is controlling your radiators?

If you count is 1 full cycle in under 10 mins, you have issue to fix. Your boiler should start, modulate down and run for a prolonged period.

100L cylinder with a 32 kW boiler takes under 4 minutes to go from 45 to 60, as it's only 1.75kWh heating capacity in the cylinder. So to get a useful run time you would need several hundred litres. Hence my recommendations

Remove actuator from valve and truly to rotate the valve with your finger. It should be easy to move. Manual valve is an isolation valve, so likely to have a handle on it. May look similar to this Do you have any drain valves upstream of the UFH but after the motorised valve. Will look like this?

1. I wouldn't bother 2.Not sure what you will gain from this 3. That just makes stuff way more complex, and sure it will gain you much. Read a few Baxi datasheets and manuals and they don't seem the most sophisticated of boilers and not the best output turndown. With this in mind, you need places to dump heat, as your summer house will struggle to a absorb the heat on offer and I would suspect your boiler doesn't run for long and has plenty of cycling, which will ultimately reduce life, but use way more gas than needed. Turning down flow temp could lead to issues with cylinder heating, so do it small steps, you need to ensure the cylinder heats in one long boiler run, not lots of short cycling, which will be the result if you trim heat too much. The ideal way to run UFH is low and slow, so I suspect the UFH mixer could be turned down. To help the boiler out, need other parts of your heating system open. This is basically a recipe for boiler short cycling, higher gas consumption than you could have. So timings I would set all the same, run whole house a little warmer. Next steps and questions Does boiler accept opentherm control? You really need to run the heating system differently, so priority domestic hot water, opentherm is an easy way to implement this. So basically you run one flow temp for cylinder heating and another for central heating.

Few things, motorised valve not opening valve. A manual valve closed in that circuit. UFH pump not starting UFH mixing valve stuck and not sucking any new hot fluids in.

There climate is a lot different from ours, they are hotter in summer and way colder in winter, which is way better than the just above freezing, high humidity winter climate we have, for ASHPs. So defrosts are way less of an issue. Then it's just a matter of sizing correctly.

Why not when it's easy to do, actual boiler efficiency has little to do with boiler model more to do with how it's plumbed in and controlled. You could probably save a good 20% on heating costs. And get way better hot water performance. So choose your combi of choice, but make sure it's controlled via opentherm, not on off thermostats. But ideally has plenty of turndown so min output is low. Not the best boiler out there, pretty poor turndown, with a min output of about 10kW, so boiler will cycle a lot at mild temperatures. The best will turn down to under 2kW. Can only run at a set flow temp. So not the most efficient by a long way. Hot water flow rate is 11.5L minute. Just looked at my old boiler and it did 15L minute at the same 35 Deg temp rise. And had a turn down to half the one you are looking at. I would look at other makes and models.

Some simplification sounds the order of the day. A couple of radiators kicking a huge boiler into life for 5 mins isn't an efficient way to run a heating system. Will wait for the additional information requested above.

But would life be worth living afterwards, "I would of or I wouldn't of" being mentioned many times, comes to mind

Solution is simple - get rid of the blockage. Either remove down pipe and unblock or leave in place and blow out debris with a hose pipe from the top. Maybe while your up there clean the gutters if that's what feeds the down pipe. Most window cleaners now do a gutter cleaning service, get them cleared every year, or if plenty of trees around more often. Fix the problem, don't cure the symptoms.

What in the rest of the heating system, as I assume you are not using 32kW just to heat a garden room?

Nearly twice the cost of the UK! That's expensive heating, a time of use tariff and direct electric heating would cost about the same when you add in boiler efficiency.

When I used a plumber, we used a firm that employed plumbers, not lone self employed ones. We generally had the run around, just like you until then. Learn what to do, it's not really that difficult, you don't even need to solder these days. Easy DIY stuff to use 1. Hep2O, plastic pipe and push fit fittings. You need a cutter for plastic pipe and that's about it. 2. Tectite push fit for copper pipe, a selection of fittings for copper pipe, you cut the pipe with a proper cutter, and the fitting simply push on just like Hep2O ones, but these are metal. Drain pipes, solvent weld or compression joint, just remember they are generally different sizes, so don't generally mix, you choose a system and stick with it. Then it's a matter of correctly sizing the pipes.

Why, they give you 15p, then immediately charge your next door neighbour nearly double that. Pretty good money making scheme.

But that isn't fully correct, because it doesn't take into account the gas standing charge, which goes when you remove the gas meter. So if your house consumed 6000kWh of gas per year your pay £377 for the gas plus £125 standing charge. So your 6000kWh cost you 8.35p per kWh, based on standard prices. Electric is 26.35p per kWh. So real spark gap is 3.2, not 4.2. And the above doesn't account for the approximate 80-85% efficiency of nearly all gas boiler installs. So piss poor reporting by Nesta

Not to any scale, drilling to tie back just keep existing facilities ticking over for longer. There is loads of oil out there and routing pipe back to existing back to an existing facility may not be easy or cost effective. It's playing at it