Recent content by Johntheo5

Assuming two new stats, if you turn one off on its on/off switch as shown, and the other (the one you say isn't working normally) doesn't switch off the boiler off "normally" and you then switch that off also, see does it shut down the boiler. If it does, leave it switched off, turn on the other...

Not sure what you mean by setting it back to III, the only "III" above is constant curve III, IF it was on this setting then would/could definitely cause problems, if now set to PPI then too low IMO. Based on my own 12 rads I reckon that you require around 3.3M to give a flowrate of 20LPM if...

You said in post #6......"Three LEDs, when firing the I is green, II and III are amber." If it is Green space space yellow then I think it should be flashing, I think all the PP & CP settings have flashing LEDs but maybe thats only while configurating it, its a long time now since I set a UPS3...

Can you post a photo of the external? Grundfos Pump while running. showing the LEDs, also show/state its model number. OK, I see you have a internal pump. EDIT. it shows a external pump in the WB MIs but you stated in another thread in reply to my same query (re internal or external) that its...

Just lift the top off and you should see something like mine, downstairs as well with the Flomasta type filler, if the filling part is offset like mine then should be OK to install the ballcock type, take a snapshot of the inside of the cistern and show it to the plumpers supplier. I installed a...

Assuming a max of 120L rads+system, the max expansion vol will be 2.5L when fully hot, my 30L F&E cistern, LxBxH, 381mmx254mmx305mm will rise by 10.4mm/liter so 2.5L will cause a rise of 26mm, say just over a inch, not a lot, depends obviously on the cistern dimensions, measure your own.

Under really no circumstances should you require that UPS3, a giant of a pump, on its max setting of CC3, which, in effect is a constant head of 6.4M up to over 19.0LPM, I'm surprised you're not getting even more carry over and air ingress, CC1, at over 4M should be adequate, one green, if not...

And the pump details ?

Gas or oil boiler/ Internal or external circ pump? If external, post make/model/mode/setting or/and a post of any LEDs when running.

Next time you vent air out of it until you get a dribble of water which should be done with the Boiler off, start up the system&boiler and then open the vent, if no water then comes out, shut down the boiler and see if water then re appears, if so, its pulling a slight vacuum at the towel rail.

Maybe replace it (yourself) with something like this, shouldn't get any water hammer (ballcock type) as it gradually reduces the flowrate as the cistern fills.

What type of filling, is it the traditional ball cock type or something like this Flomasta type, the latter fill at full throttle and then shut off pretty abruptly which may cause water hammer.

Its serious from a safety point of view if the PRV is not lifting at 3.5bar, is it??. If it is, then each time the boiler/system is cold the pressure should be a little less.

3.5kW so ~ 1.43LPM at 45C & 0.91LPM from water at its very coldest winter temp of 5C, wonder what happens if you throttle the flow right down to a trickle, does it just run hot/cold then like a electric shower when its TCO (thermal cut out) operates?.

I suppose when one thinks of a instantaneous water heater one means that the water only starts heating when there is a flow through the heater like a electric shower, there will obviouly be a small delay while the heating element itself heats up. The "boiling" HW taps are around 3.0 kW which...