3 problems, advice needed before calling plumber!

[boon147]

Morning all,

Hope you are well.

I'll cut straight to the chase, moved into a new (to me) property and have 3 problems with the CH system. My system is:

Glow-worm Ultimate 40FF (will be upgrading at some point in the next few years)
Sealed / Pressurized S Plan+ system
Header Tank with HW Cylinder

Problem 1. CH Pump runs randomly - After checking the boiler manual, the troubleshooting steps point to a new PCB. The boiler isn't smart enough to have a thermo controlled pump overrun, but a timed one. Assume the relay within the PCB is kaput

Problem 2: Loss of pressure - Gradually, over a number of weeks the pressure in the system will drop and I'm topping it up every 2 weeks. I have searched high and low and cannot find any residue of water, so I'm wondering if a faulty pressure release valve on the expansion tank is a possibility? Or maybe a faulty gauge? I have had the CH off completely and the pressure still drops, so it doesn't appear to be on that circuit, or the UFH. Occasionally, the pressure will seem to bomb to 0 instead of a gradual decline.

Problem 3: Luke-warm temp out the boiler when CH is on - This is the one I really want some advice on, so that I have a general idea when the plumber is trying to explain things to me (this is a case of little knowledge is more dangerous than no knowledge, but I just want to be sure I am not taken for new boiler if I don't need one). Anyway, the outlet for the system is hot to the touch when the UFH is on, UFH and HW is on, or just HW. When the CH is on, on its own, or coupled with any of the others,...the outlet pipe is luke-warm at best and takes an age to heat up. Again, the boiler isn't smart enough to know what's calling for it, its just a call for heat so I am wondering what could cause this? I initially thought it could be because the CH circuit size, but the UFH is probably of similar size and that heats up instantly. The heat must be going somewhere as he boiler keeps running and doesn't trip out when it gets to temp. Any ideas?

I also wondered if the problems could be linked in some way? FYI, its only recently had the pressurized S Plan+ upgrade according to my neighbour, and the sellers arent getting back to me with who the original plumber was.

Hopefully someone can shed some light. Sorry for the length, but want to be sure you have all the info.

Much appreciated.

 

[cross thread]

Pressure may be the expansion vessel needs recharging,
the output when rads required may be the kw output of the boiler ,what size is it ? how many rads ? .some boilers can be range rated to suit the output required.

 

[ianmcd]

FYI, its only recently had the pressurized S Plan+ upgrade according to my neighbour,

Page 30 diagram 9.5, check that link referred to, when the system was upgraded that link was possibly not removed

https://www.freeboilermanuals.com/assets/pdf/glowworm/ultimate40ff.pdf

 

[boon147]

Pressure may be the expansion vessel needs recharging,
the output when rads required may be the kw output of the boiler ,what size is it ? how many rads ? .some boilers can be range rated to suit the output required.

OK I'll check the vessel, all looks brand new so if its dropping like that, assume it could be faulty? I'll check the pressure and equalise it to that of the system.

I have 7 rads on the circuit, 3 look like new (ish) double panel type 22, 1 is and old towel radiator, 2 are old single panel, and the final one is a new looking Type 21. I've just put it on now to see if the heat is being pulled away quickly when in the different settings, and the heat for the UFH reaches the manifold almost instantly, along with the UFH pipes too, but with the CH, its just so slow, the rad TRV connecting pipes are the same as the boiler outlet, it shoulnt take long should it to warm at least the first rad on the circuit? I have increased the pump speed to 2 in case it was too much water for the pump, but thats made little to no difference from what I can tell. There gotta be something in the CH circuit specifically thats causing this surely? The boiler is not smart and therefore doesnt have a different Kw setting for each heat circuit, its just either on or off. The power output of the boiler is 8.79 - 11.72 KW so I understand.

Should I increase the output temp on the dial? But if that solves it, what I dont understand is why the HW and the UFH pipes are up to temp within a few minutes?

Page 30 diagram 9.5, check that link referred to, when the system was upgraded that link was possibly not removed

https://www.freeboilermanuals.com/assets/pdf/glowworm/ultimate40ff.pdf

Thanks for that, One of the first things I checked but its not running constantly, its intermittent (straight after the heat being on as expected, but then will also cut in randomly) and you can hear the relay click. Its not thermo controlled, but timed, so I just think a new PCB will fix it. Unfortunately, a new PCB wont fix the other points so reluctant to have a new PCB is I'd need a new boiler anyway.