What are the pros & cons of S plan as against Y plan
S plan versus Y Plan
- Thread starter garrytheskate
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Not a lot really.
Slightly simplified pipe layout for Y.
No bypass required for Y as there is always one of three routes available at any one time.
Few quid cheaper for Y, as a single 3 port valve is cheaper than the pair of 2 ports needed for S Plan. Plus you don't need to buy an auto bypass for the Y Plan.
Sometimes its just down to which plan suits the location its going in, or even plumber's preference for one or the other.
Sure someone else will think of something else.
Slightly simplified pipe layout for Y.
No bypass required for Y as there is always one of three routes available at any one time.
Few quid cheaper for Y, as a single 3 port valve is cheaper than the pair of 2 ports needed for S Plan. Plus you don't need to buy an auto bypass for the Y Plan.
Sometimes its just down to which plan suits the location its going in, or even plumber's preference for one or the other.
Sure someone else will think of something else.
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Sounds odd, but I prefer S plans when I cannot bung the f&e and I dont wanna drain down. Its not a problem if the h/w's return has a valve for balancing.
Mr. W.
Mr. W.
Installation of S or Y plan can largely depend on your current system configuration, where the different controls are to be situated and how much room you have. I hate to see badly designed pipework and wiring. Pumps hanging mid air and motorised valves that are hidden behind cylinders - think of the future maintenance! After all it's you that's got to live with it.
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Many thanks for the replies
The reason for asking is that the system I have at present is the Y plan with an additional zone valve between the 3way valve and the HW cylinder. What is happening when HW is called for there is a loud bang from the 3way valve. If I change it to S plan this would hopefully get rid of the problem. There is a by-pass on the boiler
Regards
Garry
The reason for asking is that the system I have at present is the Y plan with an additional zone valve between the 3way valve and the HW cylinder. What is happening when HW is called for there is a loud bang from the 3way valve. If I change it to S plan this would hopefully get rid of the problem. There is a by-pass on the boiler
Regards
Garry
No the noise hasnt been there all the time but I did replace the 3way valve + actuator and also replaced the actuator of the zone valve. Still the noise.
Regards
Regards
Not sure the way you have it configured. Why the extra zone valve to the hot water cylinder? Could be two port valve not opening before the mid position valve hence the valve seems noisy. Or am I missing something? 
At BG we were told if it was over 17.6 KW then it needs to be an S plan.
S plan each and every time purely for the amount of control you have on the system,especially when zoneing is involved I cant even remember the last time i wired up Y plan system on a new install
The only time i see Y plan now is on repair work.
The only time i see Y plan now is on repair work.
M
mysteryman
... which is a real pity because an S Plan prevents pump overrun. Why fit two valves when one does a better job?
thats what abv,s are for and as already said y plans have their limits.
you need two valves regardless on an unvented so S plan for me
also if y-plan and the overheat stat/HW valve has been wired in series with the cyl stat/hw call then you also need bypass arangements
Picasso, why the 24kw cut off point for y-plan, is this just a preference of yours?
Matt
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