Can wiring be changed to avoid bypass loop?

[SgtFoley]

Hi all
quick question....
My system: Vaillant EcoTech 418, S-Plan system, 2 zones (HW unvented cylinder + CH). There is a short loop with auto bypass valve.

System works fine but I am attempting to upgrade to smart controls (Drayton Wiser). The new controls seem to operate via short bursts of heat (to maintain temperature).
This means my boiler is not on for very long (e.g. 1 minute once the house is at temp), but cycles often (back on after 3 minutes).

Will this continuous on-off materially reduce the life of my boiler?

Also, the bypass loop is on (open) a lot... this seems wasteful.
Would it not be possible to rewire the controls so that the heating valve shuts some time after the demand has stopped? i.e. effectively using the rads as the bypass loop?

thank you!

 

[stem]

I can't comment on the life of the boiler, that would probably be one for the manufacturer depending upon the life cycles of the components they use, but personally I wouldn't think it would make much difference.

Regarding the controls, it would be possible to add a 'delay on de-energise' timer in the electrical supply to the heating motorised valve. That would keep it open until a preset time had elapsed, after which it would close. However, if the hot water happened to be calling for heat during the delay time, then the boiler would continue to heat the radiators too.

A better solution probably would be to convert it to a 'Y Plan'. The three port valve remains in the position in which it was last used, so the water would continue to circulate around the radiators and / or the hot water cylinder when the boiler goes off.

To be honest though I can't see why you would want to do this. If it's to save energy you will be disappointed. The water is just circulated through the by-pass to remove the residual heat from the heat exchanger. The tiny amount of heat that is lost from the pipes during this process will go towards heating your home anyway, and the rest of the heat will remain, ready to start the next cycle in a few minutes time. If you were to pump it around the radiators, OK the heat would go into your home, but the boiler would then have to burn more gas to heat up cooler water at the start of the next cycle.

 

[SgtFoley]

Thank you stem!

It's good to know it can be done, but I get your point on the likely lack of benefit.
I'm slightly worried the new controls (short bursts of heat) might expose the fact that the bypass loop is too short... if it turns out that way I will consider this solution.

 

[muggles]

Boiler cycling will both shorten the life of your boiler and increase your gas usage, neither of which are good things!