Nickfromwales

It might be the fuse in the manifold wiring centre. Hold fire before telling someone the fault, as the correct order of events is to get the installer back to tell YOU what’s wrong Idle thumbs etc.....

Get yourself some wet-wipes and enjoy ?

Hepworth for HRC needs to be temperature capped so a TMV is required in every instance. I’ve been using the same TMV that goes on the SA units as they’re decent reliable units. I set those to 50oC nominal and happy days. The question of how much of an arse your BCO is, whether or not they make you drop the bath to 46oC as “god intended” ( some BCO’s think they’re ‘up there’ for sure, and some are just massive bell-ends ). ??. Best to check before assuming that 50oC everywhere is acceptable.

TRV’s would take a normal actuator? Available from £5 up.

The only bit of kit needed here is the thermostatic valve, and that one is a good make and will be super-reliable. Flow control is simple to work out. Working from the biggest loop, open the gate valves 100%. For the next longest loop, close whatever % difference the difference is and keep going until the shortest loop is the least opened gate valve. Most gate valves are 13 turns so 1.3 turns = 10%. Bingo. @Gus Potter you are a pipe wizard, Potter. ?‍♂️ Love the comment about the submarine commander ?. Did you put a suitable hat on whilst frantically twisting gate valves in different directions with both hands? “She’s coming up by the stern, captain!!! Somethings gone wrong” lol. Time to start a book on how long this system will be in like this for with the door shut..... ???

You can't put colder than 12-14oC through the slab or you'll get condensation forming on the floor. Slab cooling needs to be a thing you forecast the execution of, not just switch on and it cools the house, so set it up for early prevention and not cure if you decide to include it in your design.

Fire away

You’ll need to link flow and return at source and fit a gate valve for a manual bypass adjustment. Linking the F&E will do zilch as they’re only a tiny bit apart and on the same flow pipe. ? Needs to be across where you link the PFM in ideally.

Nah, it’ll be fine. Worst part of the HWC will be the cold connection at the bottom. If that’s looking ok then the rest will hold up.

If running through the whole single pipe system as well as the boiler it’ll be fine. Have the MPV open as a bypass so the heating circuit isn’t seeing full force of the PFM. The old school boilers are pretty tough tbh. Reversing the flow is the money shot as that stirs quite a bit of crud up, as does using an SDS rubber hammer on the bottom of the rads whilst flushing. Go hard, or go home.

Seems so. Also looks to be susceptible to long runs having cooler rads at the end of the run too, vs flow and return systems.

What is the construction type? Block and brick? You'll need to parge-coat all of the internal walls and not go for dot n dab. You could just use a membrane to go from 50mm below to 50mm above the joist detail, and AT tape the hell out fo everything before covering the tape with wet plaster ( parge-coat ). This will be a bugger to detail over a whole house, but remeber that you will need MVHR or at least MV to pass building regs in an AT house.

Our hero.... LOL ?

That's its job. 24/7 The only thing required there is your absence The internal Vaillant programmable room thermostat says when and how hot, f.uck all to do with the external unit / thermometers / owt lad. Stop worrying about anything outside influencing your use of times / temps as that is done on your behalf TO COMPLIMENT the times and temps set internally. You are an END USER, not a technician. Focus on what you NEED to know, not what you'd LIKE to know. Life's too short ( yours AND ours )

The whole picture is necessary to get a full set of ( correct ) replies "Elaborate away". Yes, just a cable from the grey to the LR and you're done. That's all 230v so all good. I've never done anything less WRT earth and 230v in the same cable tbh, so someone drummed that into me somewhere! Almost every double insulated controls I've ever fitted ( and I've fitted countless number of every kind going ) have had an earth terminal for looping a continuous earth path through. That has not been connected to the equipment, but just a stray terminal set in a bit of plastic / whatever that is a junction to maintain earth continuity, should it be that a downstream bit of kit requires a reliable earth arriving at it.

Yup. Nowt lazy about that then. If you switch heating on only, you'll only get flow through the rads. Word.

Just take pictures before boarding, with a tape held up for reference measurements. Pipes are usually in the centre of the stud void so you'd have to go out of your way to strike one. Prob best to stick the foil tape to the back of the PB instead of onto the pipe.

Wont the MPV just open for heating only if the cylinder stat is satisfied? Failing that, just close the HWC gate valve until the heating is blown through. Is there a cylinder stat, or does DHW simply just get to the set temp of the boiler stat?

Did you ask Samsung how the TV works, or do you just switch the chuffing thing on and watch the nice picture?

yup. and yup.

Turning the rotary dial should be set to master override ( temporary override to be precise ) and will kick the system in regardless of the timed setting. That's so you can boost the heating sporadically and not have to interfere with timed settings or the current program. Understanding the A-Z of this at this time is a little over the capabilities of most as it's not a regularly discussed topic and nor do I think does anyone else have a split. Mention of this being quiet....how would anyone without a split know?!? Mention of a nigh time setting.....doesn't have one, just a set primary temp for 'heating' flow and a set temp to achieve on the room thermostat that it will use that primary temperature water to achieve said set temp eg by running that heated water through the radiators. Simple. If you want a night time setting aka set-back, then just manually set the dial to that temp and the ASHP will take over the thinking for you eg it will give little flow on a reduced curve and be of less nuisance. If the heating return stays cool and the stat doesn't get satisfied then the system will adjust and the ASHP will be told to up its game a little until internal conditions are met.

Just turn it up when asked....... Yup, aka 'weather compensation'. The ASHP will increase it's output to compensate for the lower temp / lower it when milder. It's so the heating curve is more palatable. @zoothorn that translates into cooler running rads when it's not baltic outside ( basic terms ). The outside unit and inside unit talk to each other, and if the system is struggling to get the house up to temp the controls will take over and the outside unit will be told to 'get it's finger out and "dump in more heat". The controls are sophisticated beyond most people's comprehension, so explaining every nut and bolt is just impractical. Hence the request for some rudimentary commands being given to cut to the chase.

You're being told asked to do something so that the folk helping can ascertain how to help / what could be at fault. Turning it up to 22-23oC will put the system into a curve that makes the heat pump ramp up. Peter wishes to see what effect that will have on the system performance so that he can continue to help you. Prob best to do as people ask, or how are they going to be able help you?

Is there a mix of UFH and radiators? Any other zone valve / heating zone(s) / controls involved? Just one household thermostat / Ctrlr? To answer you actual question ( lol ) there will be a need for a live core and a CPC ( earth ) in the same cable minimum. Therefore you will need a 3-core flex, 1.0mm2 in size, PVC / PVC type. You will use the brown and the earth, the blue can be a redundant core. If you buy 2-core flex you won’t get an earth conductor, just blue and brown The earth MUST be connected if it’s carrying 230v. You could use a smaller cable as you only need to be = or > the amp fuse rating in the fused spurs 3a or 5a should be in them max.

You can’t change to all 2-port !! Oil boiler needs an always open overrun path. Good point. Isn’t the air separator where the F&E tee’s in? Forgot about that.