Search results

Thats your problem almost without any doubt, the UPS3 is a giant of a pump and is dispatched set to full speed, III on CC3, it will be circulating at a massive head of 6.4M up to a flowrate of over 19LPM, 1.15ms/hr. Just press the setting button briefly a few times until you gret just one solid...

Your pump Head is possibly too high, can you post the make/model/mode & its setting or post a photo of it running with the LEDs clearly shown.

I have a simple FantiniCosmi digital roomstat in a combined (two rooms) dining and living room with two rads and where we spend 99% of the time, the heating is switched on at 0700hrs and switched off at 0100hrs each day, roomstat set to 19.5C during the day and 20.5C (sometimes 21C), from around...

Mechanical TRV "fully open" stroke varies with the setting, the lower the setting, the less the stroke/opening when "fully open", so obviously cannot maintain a set temperature (see below) depending on conditions, however, in tests I did years ago I found that the hysteresis, at least on the one...

Know several peoplw with these "recalled" pumps but not one of these has been replaced as of yesterday.

Why not stick a pressure gauge on the (unused) balanced cold out, if you (or your plumber) shuts the isol mains valve then the incorporated non return valve in that combination set will/should stop any water coming back from the cylinder, just slacken the blank after shutting the islol vale to...

What make/model Boiler do you have?

That pressure gauge (looks like it) measures the mains water pressure after the PRV (pressure reducing valve) and is the supply to the unvented HW cylinder, if so, has nothing to do with your problem. If there is a pressure gauge on the front of the boiler, check its reading, should be...

On one boiler, the latest version, the pump wasn't reducing speed low enough to get a fairly modest set dT of 15C, on the other boiler, (previous model), the pump speed was/is reducing far too low to 15%, to give a residual head of ~ 0.07M, 7mb, which is far too low to give a balanced flow to...

The problem is that its turning down far too much, it should only be turning down on Auto to a speed that doesn't result in the residual head falling below 100mb, you can see from the attached, this corresponds to ~ 50% ("Minimum with Auto"), with my system corresponds to a flowrate of 10.5LPM...

The available flowrate at 15% output based on a Vaillant boiler's HEX and my rads/system dT is (only) 2.8LPM, depending on the number of rads and output you can haveanything up to 5.8kW with 9.5/11.5 "kW of rads", say 6 or 7 rads but the (residual) head available is only ~ 0.07M, 7mB, not a hope...

Another reason I configured this spreadsheet is that someone with the latest Vaillant 624 couldn't get his boiler to control on flow/return temperature spread dT, settable between 10C and 20C, it doesn't, by design, allow the pump speed to fall any further once the residual head falls to 100mB...

No, its a bit generic but still I would think quite accurate, I just based it on a (Vaillant) HEX dP of 3.1M at 20LPM and a (my) rads losses of 3.44M at 20LPM, the rad calcs obviously have no effect on the residual loss, have a look at the spreadsheet which I put together some time ago and am...

I’ve been asked numerous times to explain the residual pump curves published in some Vaillant Ecotec Boilers MIs, I’ve looked at them several times but afraid I can’t make any sense of them. Someone on here might explain them or/and post similar curves from their (Vaillant) HP circ pump curves...

Asking for someone to check their Boiler.;)

Can you access the fan impeller, if so, use a screwdriver to see if it will rotate without much effort. (Ensure boiler switched off)

Some one might have a look at the pump speed, d.015, in their boiler menu if they have Auto selected in the pump settings, (last version of the 624, not the present), Someone is getting a constant 15% in Auto which is, theoretically, not allowed. It looks like ~ 40% is the minimum speed in Auto.

Just start up any zone and lokk at and post a snapshot of the LEDs. IF its running with one solid green followed immediately by two solid yellow LEDs then its running at full speed which can lead to excessive noise, while its running, just press the setting button briefly to change settings...

It's the blank plug,1, immediately below the adjusting screw, with the boiler off put something underneath the plug and slacken it right back until oil dribbles out, then retighten it, do not do this if the oil tank is below the level of the boiler. You could also use the vacuum connection plug...

Why are these heaters rated at 240V? The supply voltage in the UK has been, nominally, 230V for years, that heater will only give 4.95kW at its proper 230V rating, all the above flowrates should be X by a factor of 0.958.