Pump speed/bypass/boiler output/hot water question.

[Steve57]

We had a new boiler installed late last year, a Vaillant Ecotec plus 18 heat only. We now have a sealed system was converted to unvented hot water. Before that we had a Potterton profile 60e on a conventional vented Y system. The new system is a S system I believe.

On the old one, when the heating/hot water got hot enough, I think the boiler ran on until it reached a temperature that was safe for it to stop running. On my new one, when the hot water or heating is up to the required temperature, the pump runs on for exactly 5 minutes before it switches off.

My question is that now we are getting to the time of year when the heating is not needed, is it worth setting the pump speed (currently on speed 2 of 3) to its lowest speed if only the hot water cylinder is being heated? If so, do I need to adjust the bypass valve? Also is it worthwhile reducing the boilers maximum output or shall I leave that on maximum as it will modulate itself?

Thanks

 

[Riley]

The pump overrun is there to dissipate heat following the closure of the valves on the system. I would leave it all alone and don’t alter your settings. In the engineer settings on the boiler it’s very easy to change the wrong thing

 

[Chuck]

We had a new boiler installed late last year, ... is it worth setting the pump speed (currently on speed 2 of 3) to its lowest speed if only the hot water cylinder is being heated? If so, do I need to adjust the bypass valve? Also is it worthwhile reducing the boilers maximum output or shall I leave that on maximum as it will modulate itself?

The behaviour of an old non-condensing Potterton Y-plan system is irrelevant.

If you don't think that the new boiler is working correctly, contact the installer. Otherwise, leave it alone it's got a computer in it to look after everything for you.

If it ain't broke, don't fix it.

 

[Riley]

I just read it as fiddling for the sake of fiddling. By turning it down you might save 1P in every £1000

 

[Steve57]

My main concerns were unnecessary wear on the pump, possible wear on the boiler running at full pelt just heating up a tank of water and the noise/blast of the fan as the boiler is fitted in the loft and it exits my flank wall. When the window is open on hot evenings it’s quite noisy. I know how to adjust the maximum output (not exactly rocket science) and when it’s running at 15 kw or less, the fan/roar is much quieter. I know the rads will heat up quicker if set on maximum output but no need for a quick warm up on the water as it’s on constant anyway. No faults with it either so no need to call installer but thanks for all your answers.

 

[Riley]

If you’re not an engineer you shouldn’t really be in the background menus

 

[Steve57]

Again, thanks for all your answers. Great forum. Bye.

 

[Riley]

Steve you need to take yours and your families safety more seriously. You’ve contributed on two threads and so far you’ve adjusted engineer settings on your boiler and have tweaked a safety valve on an unvented cylinder. Both of which you are not qualified to do. I admire diy but please know your legal limits. Don’t want to sound like a do gooder but I’d hate for it to all come crashing down for you