Hello and welcome to the underfloor heating review channel, my name is Craig and I have worked in the underfloor heating industry for over 16 years now, it’s my goal to provide you with informative content that will answer all your questions about underfloor heating and show you everything you will need to know if you are considering to use this ever growing technology in your own home or perhaps future project. So I would be very grateful if you would consider subscribing to this channel and please remember to hit that that bell icon so you get notified when new content has been uploaded
Nope, no hard rules on this, it all comes to the output your trying to achieve in order to meet your heat losses, but if your talking about screeded systems then it never hurts to add more pipe regardless of the heat source
@@andypag1071 I would love too but I simply don’t have the time with young children and being active in the industry as my job. Maybe one day but I read all of the comments
Clear and concise, thank you . I’m attempting this install but I only have to add 50 sq.meters of ufh to part of house that is on far side from baxi .I dug down 200mm in old stone section of house added 100mm insulation. I’m putting in the loops . A plumbing friend tells me the aluminum breaks down in the piping but I just used it anyway as everyone else uses this product in my area (ufh specific pipe from Italy) Question - can I keep single stage boiler , keep the water tank (immersion from boiler ) Keep the on off switch for rads (old style just which has temperature control on the baxi (on/off) And on my new ufl 4 port manifold just supply it from the 3/4” radiator main supply (at end of rad system) ? Perhaps I’m better of getting new thermostat, wiring control center and redoing all the controls with two thermostats (rads and ufh) Pump and boiler heat on for rads Pump and boiler heat on for ufl Controled from thermostat and or smart phone
Hi Robb7177 Thanks, would not worry about the Ali pipe it very common and long lasting these days, as for the set up I would always recommend having the two systems seperated and independantly controlled not just for best practice but also userbility.
Nothing wrong with using 12 or even 10mm pipe in UFH systems regardless of the heat source if the products are designed to suit. End of the day it’s all about flow rate, output and especially buildup. Many options out there so don’t let it put you off if you see smaller diameter pipes that allow you to add UFH to your home
Hi can we use two different pipe sizes with same manifold using an adapter. I'm thinking for using a 16mm pipe for my kitchen which has a larger area and 12mm pipe in hallway with wood floor which i will take out n install 60mm insulation between 100mm joists.
At 8 minutes 30, you explain the signal is sent to boiler or potentially the 2 port after the call for heat. What is the need in the 2-port to the manifold when you’ve already got more than enough control?
Hi, if it’s just an underfloor heating system then the two port valve is not necessary, the two port valve will allow the radiator part to function correctly, hope that helps
Hi @Waldenpons, ideally when you get your boiler/ heat source serviced, if it’s been a few years then I would think about getting it sorted later this year
Quick question, i replaced an actuator once it was connected the zone were the actuator belongs to (3 actuators) is calling for heat and turning on the pump and it will not shut off. Any idea what is causing it. ( a transformer was changed during that service).
@@Waldenpons really hard to say but actuators do come in two flavours so to speak, normally open and normally closed, if the wrong one was installed it would act in the opposite way
Thank you very much, very informative. Should the UFH pump be wired to run simultaneously with the zone valve being opened and the boiler being called for heat? or Should the pump come on when the thermostat signals the zone valve to open beforehand?
Hi euanowen, that’s a very good question. From my experience it will run when the signal is sent to the boiler/ zone valve, that being after a short delay from when the stat calls and the actuators are given time to open. But I am sure different wiring centres have different setups. Hope that helps :-)
I have a Wirsbo brass manifold underfloor heating system installed in 2005 with electromechanical actuators on the manifold ports and thermostats which control this. Can I replace those actuators with a manual flow control so I can just set the rooms I want heated to be open and those rooms I don’t use i can shut off? I’m trying to get rid of the power consumption of the actuators and thermostats, plus I heard underfloor heating runs more efficiently if you leave the zones open and control temperature by adjusting the boiler flow temp.
Hi PVflying, thank you for the comment, if you want to remove the actuators then its just a case of working out if the port is open or closed once the actuator is removed, in many cases they are open when the actuators are removed but not always the case, a screw cap can then be put in its place to close them (normally supplied with the manifold) Leaving zones open and just controlling the flow temp can be efficient but only in some circumstances such as a very large system with a large thermal mass (screed), in these cases the stat has unable to change the room temp quickly due the the heat or lack of in the screed. I would leave it alone or just shut down specific circuits if you really don't want them to be heated. Hope this helps and good luck.
@@underfloorheatingreview thanks! If I experiment by powering off the wiring centre that would cause the actuators to all be off, so I guess if that proves that the heat then flows to all zones I suppose I know that it’s safe to remove the actuators as it proves the default is for the zones to be open (as opposed to needing the actuators to press the pin down to open the zone). If this sounds right to you I’ll have a go and see what I can learn about my system
Thank you for putting this video together, it's very helpful and very well delivered. I have a 3-Zone system, kitchen, living room and hallway, they are each around 80 m run ufh pipe. My build never explained anything how to operate. When I used the underfloor heating it gets hot at the beginning part of the pipe like 30% you can feel it on your feet, the rest is generally cold uncomfortable to walk on doesn't get hot. The flow rate is around 3/4L on each zone. I've tried to play with the pump and put it on a higher setting didn't really make a difference. Any advice you could shoot my way would be greatly appreciated, as I've been ripped off on my first round :-( Thanking you in advance
Hi parmbansal1, thank you for your comment, pretty tricky to diagnose online but can you tell me what type of system it is, i.e. within a screed? Worth trying to run the system for a long period of time to ensure the floor has time to heat up and touch the 3x flow and returns to see if you can feel or measure a difference between them
It is typically that the system has not been designed properly such that the circuit on question is too large. Rooms sometimes have two or more circuits to alleviate the problem that you are experiencing
I have moved into a house where the UFH manifold appears to have been installed the wrong way around: flowmeters on return and TRVs (with thermostat actuators) on flow (hot water in). The system works, but the flow meters always show zero. I assume to make the system work at its full efficiency the manifold needs to be planned the right way round (the reverse of what mine is)?
Hi good explanation of the system. However you did not explain the auto vent valves and drain and pressure release parts at the end of the manifold. My top auto vent valve is leaking. I assume I need to depressurise before removing and replacing/ cleaning?
Thanks for the great video. One question; I noticed that the on the UFH manifolds in my house the Actuators are on the ‘Supply’ arm and the Flow indicators are on the ‘Return’ arm, which is the opposite of your diagram. Does that matter ?
Hi, Flickspot, some manifolds have different configurations to the one I had shown but take a look at this for a little more detail omnie.co.uk/omnie-precision-flo-2018-manifold/?resource=Underfloor%20Heating
In your example would the underfloor circuit need some form of hydraulic separation (close coupled tees or low loss header) between the ufh zone valve and the manifold to stop the underfloor heating pump affecting the boiler's own pump? Or does the underfloor heating pump not affect any pressures in the primary flow and returns from the boiler ? I hope my question is clear as I need to understand this. Thanks
Hi, thanks for the comment. If just using UFH only then this is not and issue, however when using rads and UFH combined its best to install a low-loss header, that's what I did :)
Hi there, great video. I have a question about how wire up the heat miser properly. I have 4 zones UFH at my ground floor premises and radiators upstairs my bedrooms. It all fed by Worster Bosch boiler . I have two ports valve installed for each one - radiators system and UFH system. I have 5 core cable between the boiler and the heatmiser. The boiler is controlled by RF Honeywell thermostat. My question is if you could help me wire the two port valves to the heatmiser, as there is only one slot for two port valve . And the other one is how to wire the boiler to the heatmiser? Do I really need 5 core cable to the miser. Appreciate for any help. Thank you
Fantastic conent - with heatpumps becoming more popular which can reverse their cycle and provide cooling ( during hot summer days), will conventional manifolds work or will that need a different set up?
Brilliant content, do you offer a service to calculate and design snail pattern pipe layouts? I have my heat loss calculations for a self build low temperature system, radiators up and ufh ground floor, but I'm struggling to understand how i get the ufh to match a certain heat loss requirement. Example: a 22m2 room will need filled with pipe regardless, but how do select the pipe centres required for that heat loss and then fine tune it. 50mm spacing jumps make a lot of difference to kw heat output.
You need to know the heat load for each room, although ultimately the most efficient design is always 100mm spacing because that keeps your DT down and that makes for a high COP. The most efficient design will always use more pipe, but this is generally a good investment.
Yes and other factors such as flow temp and the floor finish will effect this, in most cases companies will over spec so that losses are met, for example some companies will install all pipe at 100mm ctrs regardless of the load, this allows them to future proof the design so if for example the customer wants to use a heat pump in the future then the system will still work at a lower flow temp
@@underfloorheatingreview But if I only do this calculation for amount of pipe required, then isn't there a risk that after installation it turns out that I haven't put enough pipe in to meet the required heat load (no matter how much I increase flow temp)?
@@AwestruckChemicals if your concerned and the property has high losses then I first recommend finding this requirement and calculating the W/m2 required - you can then compare this with the outputs of your chosen UFH suppliers system
Hi Christine, thanks for the comment, they can be cleaned but the system will need to be properly flushed, dark fluid in the system is not uncommon but suggests to me that it would be a good time to service your system and refill with water / inhibitor to keep it running correctly
At Christmas I had to have an old Drayton actuator valve replaced on my UFH manifold and also the three port valve changed. I’m finding when the underfloor heating is on the pipes running into the radiator and hot water motorised valves in the boiler cupboard are roaring hot. Both valves sound to be running although the indicator lights are not ignited as they would be had I turned the rads and hot water on. Any ideas?
At Christmas I had to have an old Drayton actuator valve replaced on my UFH manifold and also the three port valve changed. I’m finding when the underfloor heating is on the pipes running into the radiator and hot water motorised valves in the boiler cupboard are roaring hot. Both valves sound to be running although the indicator lights are not ignited as they would be had I turned the rads and hot water on. Any ideas?
Great video... A question for you. I have a fairly large system, two UFH manifolds, one hot water cylinder (mains pressure) and two radiators circuits. Recently had some issues with rtn flows not letting rad circuits to get warm, so had some of the supply and rtn branches replumbed in 28mm copper so ALL circuits come off the 28 and rtn to a 28 common rtn to the boiler. However, the UFH heating manifolds (Myson Premier) are not managing to keep themselves stable. Set them to 40 and yet they go up to 55degrees. I do not think its leaking mixers as they both started playing up when the supply/rtn branches were replumbed in the main boiler room. I have a hunch that they are reverse feeding from the CH rtn when none/few of other circuits are open and thus the auto bypass valve is letting a lot of flow to "short circuit" the system. Specifically when i first turn the UFH on, the rtn output from the manifold gets hot "very quickly" which i would not expect. Thoughts? Seen this before? Contemplating fitting non-rtn valves on the CH rtn from the manifolds to stop this.... BUT as the UFH mixer actually draws water BACK from the CH Rtn when it thinks it needs to cool things down this "could" cause a vacuum. Thinking.....
Does it draw water from the return? Or does it just use the water on the return arm of the manifold to cool and only draw from the flow when extra heat is needed?
I'm thinking the manifold never draws water from the heating return . It only draws hot water from the flow when it needs to heat up the underfloor flow temperature. The cooler water is drawn from the return arm of the underfloor pipework.
Which pipe is better for ufh in screed new build standard? Evoh or alu? Im also wanting to use 16mm pipe to do my upstairs radiators too, over sized for lower delta T and linked via a ufh manifold in a radial layout. Are all manifolds suitable for this or only some of them?
Hi Dan, pipe type is really personal preference or whatever your UFH supplier offers, i have used both without issue. As for the manifold/s then its best not to run your rads off the UFH manifold as the temp required will be higher than that of the UFH system
@@underfloorheatingreview i was going to use a second ufh manifold upstairs separate to the ground floor one using two 2 port valves. Radiators set at 60 degrees so less blending as per your video. Emetti do a manifold just for radiators but its jhst identical to all others unless its different material. I just didnt want to select evoh pipe if it was lesser quality
Great video, I have two questions. 1. Can you have some areas/rooms on open circuit, so they come on when any zone is calling for heat, ie a central hallway on open circuit? 2. Can you pipe an UFH circuit to a ground floor bathroom towel rail and if so, would you have it on its own circuit or part of a room floor loop?
Hi Dan, 1. Yes this is possible and done often, just remember your loosing the ability to control these circuits, you can always change this later 2. If you need to run a towel rail off the UFH manifold then remember it will only get as hot as the UFH flow temp so i would consider oversizing it or run it off a rad circuit if possible
Great video and really helped me understand our system. Have Polypipe UFH in 2 areas; ground floor bedroom/bathroom extension on one manifold & thermostat ( all working well), 2nd in large lounge/kitchen on 2nd manifold & thermostat/programmer which is not reaching all parts and rarely gets to the temp set. The 2zone valve was changed and plumber returning to fit new actuators/pin valves. Hopefully this will sort it unless you think there could be another problem. But to complicate matters, we also have radiators to the old part of the house both upstairs and downstairs controlled by a 3rd Polypipe thermostat/timer. This all works ok some of the time but on some days despite the thermostat calling for heat the boiler doesn’t come on, all the radiators stay cold. Are the two issues linked do you think? How does the radiator part of the system relate to and work alongside the UFH? I’ve tried to find any logic to when the radiators do not come on but can’t find any. Any suggestions would be very welcome. Thank you so much.
The radiator circuit will have its own thermostat, timer and zone valve. If the radiator circuit is not coming on when you ask it to , one of those three components is faulty.
Hi Anthony, glad you liked it, yes manifolds for just radiators are becoming popular because of the control options, the manifolds are less complex as the mixing valve and pumps are not usually required, hope that helps
