marshian

Fantastic - well done

I think you previous issues with peeling was down to you using a wood stain “paint” You can get tinted oils or let it weather naturally and use a clear preservative oil

The weir in the diverter should not be higher then the top of the tank being filled ideally it should be ~1 cm below it so when the butts are full so is the weir in the diverter and all rainwater in the down pipe flows to drain and the level in the butts does not reach overflow point

Still interested in the Gas Boiler being used because if you are modelling heat ouputs from the floor based on a boiler flow temp (no mixers or blending) you might find that quite difficult - if you have got a boiler that will do low flow temps and weather compensation then if you are all UFH then you’ve no need to mix or blend and circuit control becomes much simpler - just flow rate changes through the circuits to balance the heat output required

I’m looking at a similar set up for my HW (PHEX with my current tank which is a 2012 115 litre copper tank - spray foam lagged) Tanks with 3m2 coil area are £1300 - £1500 but I can get a PHEX kit for £450 and try it on the existing tank - if it works well I can get a high quality Direct HW tank (no coil) of a sensible size later as an upgrade for £600 - £700. Overall it would be saving against a Modern HW tank with 3m2 coil if it works well. I’m using gas boiler but running low flow temps for CH but because of the small coil in the current HW tank meant for higher flow temps when doing a 45 min tank heating cycle with a flow temp of 64 Deg C I’m only in condensing mode for the first 10 mins I’d like to heat the tank to 50 Deg C and be in condensing mode the whole cycle so 55 to maybe 58 Deg flow temp with a better heat transfer from PHEX keeping the return tenp below 54 Deg C

my apologies - I thought you were trying to use an existing HW circulation pump (the sort that stops you having to wait for HW at the taps) to also circulate the Tank water through the PHEX

Is this to avoid using a dedicated pump for the PHEX? I’m not sure I’d want a pump set up for DHWC to also be used for Tank circulation whilst heating using PHEX. I would have thought you would need to optimise the circ pump to work with the PHEX to maximise heat transfer? you are adding to the circuit the PHEX has to work with increasing losses (even if the pipework is lagged you will get some) DHWC pumps are run at low flow rates and take from the top and return to the bottom in order to keep the tank stratified. I guess for a PHEX you could take from top and return to bottom but surely better to maximise differential temp at the PHEX by circulating from bottom and returning to the top?

Yes the alignment of the hatches make my teeth itch……

Top tip for large water butts that have multiple strengthening webs Add buoyancy inspection hatches from yacht chandlery store makes cleaning once a year with a jet wash so much easier Obviously not required for non opaque containers 😉

I’d rather do that on the ones that go green due to sunlight the cladding at the bottom is temporary (will clad to match the new decking next year) other butts (side alley) Back of garage Both will be done in feather board next year to hide

Attempts to change @Kelvin’s opinion

Jesus that is shoddy!!!

In winter when we have minus temps what is the plan?

simple questions from me what gas boiler, what’s it min modulation rate and what flow temp are you targeting from the boiler? why am I asking this? I’m using a gas boiler on weather comp with only rads (13 with 135 litres of circuit volume) no UFH. House has a heat loss of 4kW at -2.5 deg C At 10 Deg OAT the boiler target is 23 Deg C and at -5 Deg OAT the boiler target flow temp is 36 Deg C (we don’t see that OAT very often) For all the Viessmann boilers good points it struggles to not overshoot at the 10 Deg OAT flow rate and I think a practical min is probably closer to 28 Deg C but it has a neat party trick that helps to reduce cycling so I’m comfortable with the level of cycling in the shoulder season. Boiler is a Viessmann “Heat Only” 16 kW range rated to 4.0 kW however has been set up with DHWP so RR is ignored for HW My previous boiler practical min flow temp was 45 Deg C with a 10 kW min output

Second one fitted - lessons learnt from the first one helped. It’s snug in the corner and I couldn’t add another down pipe support but it’s OK as it is. There is a quick way to remove and check for blockages and a hard way Easy way - slide up the upper body and the lower section will lift up and out. I’ll try the method on the one I fitted last night which was a struggle to do it the hard way - slide up the upper section, twist and remove then the lower section.

Now you've gone and done it

OK makes sense - I was just trying to work out how you came to the conclusion that 17 in terms of Heating Deg Day number was equivalent to -2 OAT Range rating boilers I'm a fan of - mine is currently range rated to to min on CH The actual min is slightly higher output than manufacturers info would imply (because Min output at 50/30 is 3.2 kW and at 80/60 is 2.9 kW - as I run 34/27 as an absolute max I think the min output is closer to 4.0 kW so pretty well aligned to my house heat loss at -2.4 Deg C OAT DHWP has full fat output so RR'ing has no impact And if heating 24/7 then I agree the house has the ability to "buffer" sudden changes outside @SteamyTea will shoot me if I start talking about thermal mass so I won't but the house can give back - maybe it will lose a but of room temp but as soon as conditions outside change it's going to recover. If that became a problem I can always increase the RR value to give the boiler a bit more wiggle room Yeah I can agree with that.

Oh please don't take me the wrong way - had I been 40 years younger I'd have a 3D printer and be printing one myself - it's a great find from a "what can be done" perspective and was quite an engaging video so 100% thanks for sharing.

For anyone that wanted a link - here it is Rain Harvesting Downpipe Diverter, Round Downspout Diverter with Filter for Rain Water Catching System (DDIV601, 75 mm / 90 mm) : Amazon.co.uk: Garden The old ones I am replacing when last on sale were a similar cost - even back in 2006 when I first purchase they were just under £15 each

Very interesting - clever design work however I don’t have the time (or a 3D printer and stocks of different filaments) Like most people I want something that works out of a box that I can fit and forget that meets the criteria (no wet walls, high water recovery rates, switchable for winter /spring/summer/autumn, doesn’t block up or if it does quick and easy to clear and most importantly doesn’t stand out on a white down pipe) I’ll do an unboxing and or assembly guide as the instructions are pretty thin if people are interested to show the features of the Australian ones when I fit the next one?

I can but I can make it easier than my journey (to get them from Australia and wait for them) as now I have one I googled the part number and they come up in Amazon EU) so I’ll link to that when I’m on a PC meantime heres a better picture of the old ones I used to use - next one to replace lever horizontal shuts the flap and it harvests - lever vertical is winter setting (nothing goes to the water butt)

Back in 2006 I got utterly piddled off with std DIY shop rainwater diverters (we had a few water butts dotted round various gutter downpipes for general garden watering) Reasons why….. 1. they blocked up really fast with moss or leaf debris 2. any decent rainfall and they had limited capacity to harvest all the rainwater coming down the gutter 3. In decent rainfall they tended to soak the walls 4. Slugs loved them and made good homes in them 5. Had to remove them in winter and replace with straight pipe to stop the butts being filled and then the water freezing. I searched the internet and found what I thought would be better. UK made, switchable so a harvest position and a divert to drain position. Decent depth before the overflow was reached (maximising volume harvested in a good rain shower. below is what I found only I bought the version made in white 19 years of use and exposure to UV has meant they are past their best (Brttle and leaky) but worst news of all was the company that used to manufacture them had gone under and they were out of stock everywhere so the search was on for replacements who knew it could be so difficult…….. Seems all the usual places just stocked the std ones with all their issues Then Google took me to Australia and I found what I’m looking for I bought 3 and tonight I fitted the first one can be removed easily without stripping downpipe has recirc back to soakaway if butt is full has leaf/moss filter/ switchable for winter Claims 600 ltrs per hour with garden hose but 1200 litres per hour with 32mm pipe (so I’ve fitted 32 mm pipe version) being Oz spec 75mm diameter downpipe fittings i had to create so adsptors to suit the UK 68mm but not exactly tricky

Slight threadjack Can you share how you worked that out? Really Interested in that aspect I've always used HDD with @ 16.5 base temp - for a couple of reasons 1. once the average outside temp gets below 16.5 I am pretty much guaranteed to need CH 2. my historical data is all based around that base temp 3. the regression calculation on the HDD site all came back with 16.5 was the optimum base line for this house. With recent improvements that may well change this winter......... PS the data presentation is good I very much liked the scatter plot of energy used v HDD tempted to do similar with my 30 min data from Octopus

Oh FFS of course it should be - has @SteamyTea hijacked your log in

Also my favorite (works well unless you tolerate a house kept to temps far below accepted norms in which case all bets are off) Example - I used 8701 kWh of Gas in 2024 Of that 1758 kWh was for HW and cooking So for my space heating needs (ie the heat loss element of the energy usage) I used 6943 kWh of gas. we heat the house for effectively 8 mths of the year so 240 days a year so 0.82 kWh heat loss over the heating season but that's not representative of the true heat loss in the depths of winter. If I take Jan as my worst month from a heating perspective I used 1854 kWh of gas divide that by 30 days x 24 hrs and you get 2.6 kWh heat loss but as the average temp for Jan was just 4 Deg again it's not a true measurement of heat loss in the coldest period For that I need to go to the 8th to 12th Jan where night time temps were consistently well below freezing and day time temps only just above it giving an average of -0.7 Deg C That period I used 397 kWh in 120 hours or 3.3 kWh heat loss I'm pretty confident as a result that my Heat Loss calcs of 4.5 kWh at -2.5 Deg C are validated For Heating season 2025/6 I've improved/increased my loft insulation as well as a few ventilation related improvements and I think this will bring me at or just under the 4.0 kWh heat loss at -2.5 Deg C