Recent content by Johntheo5

Yes, but it seems that some will also start the boiler and others will not, like the (my) Honeywell, and while most wouldn't dream of draining or refilling a system without the power isolated, it can happen, but the valve MIs don't mention if the microswitch is made or not if the valve is opened...

Do you mean the boiler will fire up when the (EPH) valve is manually opened?, the Honeywell does not fire the boiler but when the valve is powered open then when the valve has passed the manually open position, the lever just falls (down) out of the latch so when the vale is de energised then it...

Do the above behave like my Honeywell ones in that when opened manually they do not close the microswitch to start the boiler?. This facility is normally used when filling the system.

If you don't wish to split the pump to inspect it you can just view it by removing the pump and look in at the impeller from the inlet port. And the same pump with the head removed.

You should give the F&E Cistern a thorough clean out before refilling the system. Also consider isolating the pump, remove the 4 stud bolts and pump head and clean out the impeller vanes with. a steel scriber or small screwdriver and a tie wrap, those Selectrics are outstanding pumps.

Again, as stated above I think, the increase in pump press is a indication also that there is water in the system so I wouldn't, rule out the pump completely, especially if old, if the boiler has a pressure gauge then you should see the pressure increasing by around 0.2bar when the pump starts.

What is the exact model Grundfos pump? If its a 6M UPS3, then guaranteed problems running It at speed 3 if the pump is healthy, try speed 1.

The series 4 Vaillants are heat only boilers and as stated above have a external pump so have a look at its mode and setting.

I would think that the coil would emit at least 20kW especially if/with a flowtemp of 80C. I wouldn't expect a coil dT of more than 10C, if so then the flowrate required would be 28LPM, IF the actual flowrate is 15LPM, then at 20kW, the coil dT would have to be 19.1C, again unlikely. If the...

These, I think are limited by the 12LPM regulation for mains boosting, is this flowrate good enough for you?

For interest, what does this manual procedure do?, does it, like some A rated circ pumps, speed up/slow down/almost stop the pump, for about 10 minutes?.

It may not help at all to raise the CH temperature but it's the same body of water that's circulated and it may contain some entrained air that can be more easily removed via rad vents or whatever when it's hotter??. This looks like your control panel?.

I suppose having the boiler higher than the cylinder doesn't help but one would think it should be possible to get rid of that air, there are probably a good few systems about like that. In PDHW mode, the boiler flow temperature is normally boosted up to maybe max, say 80C, but don't know if...

Certanly doesn't sound right to me, PDHW is quite common. Can you confirm that the circulation through the HW coil is from top to bottom, top pipe will obviously be hotter than the bottom. Also a photo of the AAV, position on piping etc. What is the boiler pressure?. Does the Gledhill Lite...

I know somebody (UK) that has a ~ 2 year old ecoTEC 630 which has a very, IMO, useful feature, in that it can control the circ pump speed to give a settable (flow/return) dT of 10C to 20C., unfortunately this does not work on this boiler, Vaillant Technical couldn't really offer any fix, except...