No, the instantaneous HW output from the combi, if needed, could be fed to a tap close to where the boiler was located. The CH flow and return from the combi would be used to heat the unvented cylinder as with any normal S Plan.Would the DHW feed into the mains feed for the cylinder
How would that work in say the summer period where no CH is utilised ?No, the instantaneous HW output from the combi, if needed, could be fed to a tap close to where the boiler was located. The CH flow and return from the combi would be used to heat the unvented cylinder as with any normal S Plan.
Think about it. Why would it not work?How would that work in say the summer period where no CH is utilised ?
If you know how an s-plan works, then you’ll understand it’s not the central heating that heats up the cylinder.How would that work in say the summer period where no CH is utilised ?
Eh? Sorry Chris but did I read that right? or is it just the definition of central heating?it’s not the central heating that heats up the cylinder
the key is to what the words Central Heating actually means. The name central heating originally came from some wise chap who thought 'lets have a heat source located centrally within a given location to heat up water (could be part of an HVAC sys etc but for this example we'll keep it wet) in pipes and then radiate that hot water out to radiators in each area to heat up the space'. That same centrally heated hot water can also be diverted, via a valve, to a HW cylinder coil and heat that up, producing hot water at the taps.where no CH is utilised
What I mean is, the central heating doesn’t need to be on to heat the cylinder, obviously I know it uses the same circuit.Eh? Sorry Chris but did I read that right? or is it just the definition of central heating?
Makes sense. With the S-plan then, since the CH feed is used for both cylinder and rads, does that mean both can be heated at the same time ? is that advisable ? and how does one control the temps for hot water and the rads as there is only one control for CH.the key is to what the words Central Heating actually means. The name central heating originally came from some wise chap who thought 'lets have a heat source located centrally within a given location to heat up water (could be part of an HVAC sys etc but for this example we'll keep it wet) in pipes and then radiate that hot water out to radiators in each area to heat up the space'. That same centrally heated hot water can also be diverted, via a valve, to a HW cylinder coil and heat that up, producing hot water at the taps.
If you don't run the central heating then it won't heat the water in the cylinder. That gives 3 options.
1) run the HW outlets required from the combi, kinda defeats the purpose of having a cylinder
2) heat the HW in the cylinder by an immersion element (leccy), much more expensive
3) have cold showers & baths
With a room thermostat for the heating and a cylinder thermostat for the hot water. Yes, both can be heated at the same time, this is why motorised valves are used, as they split off the heating and hot water or both on at the same time, same as a conventional or system boiler, just with the added hot water draw off being used at one outletMakes sense. With the S-plan then, since the CH feed is used for both cylinder and rads, does that mean both can be heated at the same time ? is that advisable ? and how does one control the temps for hot water and the rads as there is only one control for CH.
Would the wiring be the same for the combi as it is for the system boiler ?With a room thermostat for the heating and a cylinder thermostat for the hot water. Yes, both can be heated at the same time, this is why motorised valves are used, as they split off the heating and hot water or both on at the same time, same as a conventional or system boiler, just with the added hot water draw off being used at one outlet
Pretty much. It’s only the switch live back to the boiler.Would the wiring be the same for the combi as it is for the system boiler ?
In the case of a system that is running say a cooler water temp for rads but needs to run hotter to get the HW up to 60Deg then Open Therm protocol (OT) can be used with smart controls. That will allow the system water temps to be controller directly at different times. Then it comes down to time planning whereby you are heating the HW mainly outside when the radiators are to be used. Combi's can use OT.how does one control the temps for hot water and the rads as there is only one control for CH
The problem is I use weather comp with 24/7 low temp heating so managing the differing temps is a tricky affair. The combi is an annoyance since DHW turns off the heating.In the case of a system that is running say a cooler water temp for rads but needs to run hotter to get the HW up to 60Deg then Open Therm protocol (OT) can be used with smart controls. That will allow the system water temps to be controller directly at different times. Then it comes down to time planning whereby you are heating the HW mainly outside when the radiators are to be used. Combi's can use OT.
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local