S-plan+unvented cylinder with combi ?

[Madrab]

Of course, it runs on HW priority due to the way combi's are set but if that's only on one tap then it's only in DHW mode for the duration that the tap is on then it'll switch back to CH mode. Unless the HW tap was running for say 10-15 mins then the CH shouldn't cool down a huge amount.

As far as the CH is concerned though, when the HW cylinder calls for heat then the system does need to heat the cylinder up to 55-60deg, therefore the system will need to run hotter to obtain that temp. That can be setup through the smart system controls and controlled through OT. The cylinder could also be moved to a HW priority system and then it can be run at max temps and heat the cylinder in the shortest time possible.

 

[omph]

Of course, it runs on HW priority due to the way combi's are set but if that's only on one tap then it's only in DHW mode for the duration that the tap is on then it'll switch back to CH mode. Unless the HW tap was running for say 10-15 mins then the CH shouldn't cool down a huge amount.

As far as the CH is concerned though, when the HW cylinder calls for heat then the system does need to heat the cylinder up to 55-60deg, therefore the system will need to run hotter to obtain that temp. That can be setup through the smart system controls and controlled through OT. The cylinder could also be moved to a HW priority system and then it can be run at max temps and heat the cylinder in the shortest time possible.

What kind of smart system controls are you talking about it ? Presumably opentherm load compensation ?

 

[Madrab]

Presumably opentherm load compensation

Smart controls in the sense of programmable, learning, interconnected etc and are ideally OT enabled with WC/LC.

 

[old duffer]

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

that wise man was called Bob...all hail Bob

 

[cjcoffin]

How would that work in say the summer period where no CH is utilised ?

As with a standard S-plan you would need two motorised valves and a dual-channel timer, the HW timing and valve would be used on its own in the summer.

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.

I have got it so the HW demand also inhibits the weather compensation by opening relay contacts in the sensor circuit. This means the CH flow temp is boosted to 60C which gives a faster warmup in the mornings.

 

[cjcoffin]

Duplicate post

 

[Phil1986]

Yes its doable, the 2 zone valves control the central heating water to heat the rads and/or the cylinder coil.

Please could you give me a call on ***** ASAP in regards to a his and her shower please.
I can't find another way of contacting you my friend.
2 thermostatic 3way shower valves, 6 body jets on each shower. With an over head on each and 2 hand sliders, sliders will never get used.

We have a 220ltr unvented cylinder directly above this room and it only supplies the ensuite and family bathroom. Seriously could do with some advice about this as I can't progress with my bedroom, ensuite and walk in wardrobe till I get this piped up and working.