Yes
have you got the integral 2 channel programmer fitted ?
looking at the latest supplied information,info helps
. A repair to prevent gurgling/boiling over warming the plastic expansion tank needs to be sought.
Alterations should include wiring the pump to the boiler,fitting a system bypass,converting to sealed system,ensure the radiators actually need the full boiler output and anything else following onsite investigation.
straight forward repair to bring it up to how it should have been installed
Hopefully the boiler or the system is not already damaged
Hi Hot&Cold
No i don't have the Alpha 2 channel programmer, but do have a 2 channel setup now as we've had a hive thermostat and receiver installed.
The pump is currently wired to the boiler, but straight after the boiler (ground floor at back of house) on the flow pipe before the vent. The vent is two floors up in the loft, and two rooms across, so moving the pump into the loft is going to be a nightmare wiring wise, unless i could run cable on the outside of our house maybe? there is one of them white wiring boxes up there but i doubt there is any connection in there that goes back to the boiler to connect the pump to. I think its just switched live that will be going to the boiler for when the stats call for heat.
We do have a system bypass that links from the flow back to the return before the two 2 port valves.
That's the bit I was looking at, it shows the pump powered from the boiler, so can give a timed overrun when the live heat demand input ends. If the pump isn't currently connected like that, it should be. I doubt whether it would cure the main problem though.
But I don't fully understand the circuit diagram. I assume that when the external controls call for heat, 240V is applied to terminal 1, the boiler fires and the pump runs. But where does the 240V out from 2 or from 1 via the link, go to, and why?
The diagram doesn't distinguish between a 3-port or 2 two-port valves, but it doesn't need to. The controls tell the boiler to fire and the pump to run when needed, and the valves determine whether it's for HW, CH, or both. Depending on the type of 2-port you have, each most likely has an auxiliary switch inside. The switches close when the valve is fully open, and are connected in parallel, to tell the boiler to fire when one or both switches is closed. This is to avoid the boiler firing with both valves closed, as could happen if it were fired directly, and the valves failed closed.
But I assume the valves are wired up correctly, along with a progammer if any, and that part of it is working OK.
As far as wiring is conceraned I'm pretty sure everything is spot on. All valves open when required. pump runs when required, and shuts off when required. I'm sure its just the plumbing where the issues lie.
Just to answer this point - it's the vent being tee'd off a pipe I was talking about, not the cold feed. If on your sketch you follow the pipe down from the vent above the F/E tank, the tee is the first junction you come to. I assume that point isn't in the loft.
Incidentally, if your sketch shows how it is physically, I wouldn't do it like that, as the circulating flow can shoot straight up to the vent, and exacerbate the risk of pump over. Better to tee off a horizontal pipe.
I missed some of your other questions, I'll try to come back on them later.
I thought thats what you were refering too. yes that tee is in the loft. Everything bar the rads, boiler and pump is in the loft space, and pictured earlier in the thread. You can see that tee in the actual picture.
The 15mm pipe could be a bypass, to avoid a boiler no-flow condition. Does it have a valve, manual or auto? Some bypass valves are automatic, and only bypass when necessary because everything else is closed e.g. if all the rads have TRVs and they all close. Is the pipework to/from the cylinder coil 22mm? I don't think the 15mm pipe would cause a problem, your glug or otherwise!
Has this problem only arisen recently?
The 15mm pipe isn't the bypass, as I can see the bypass separately. That is also a 15mm pipe, but that goes from flow to return before any of the 2 port valves, and has a manual red handled isolation twisty thing on it, its open by about 2 or 3 turns from closed.
The 15mm pipe in question goes straight to the cylinder 2 port valve, and on into the cylinder coil.
What I have also just realised tonight after taking some of the lagging off, is that the cold feed is only a 15mm pipe but enters the system just after the tee from the vent at a 22mm pipe(is this ok, no alarm bells with the differing feed size to the actual 22mm circuit?).
The problem i think has become more apparent after having the hive system installed, as before that was in place I only had a single channel clock, meaning heating and hot water was on at the same time, but both still being controlled with a tank & room stat. I'm sure the problem was still there, but i'm probably more aware of it after trying to keep my eye on the system to work out how long it takes for my cylinder to warm up, to save warming it unnecessarily. However, on top of this i have always had air issues where I've needed to bleed rads etc through the winter when things were in use more, and have always suspected the system being set up wrong. I've also recently had kettling issues at the boiler, so have cleaned drained and refilled the system ready for winter. I think as I've got more attention on the system at the mo its just all at the front of my mind and i'm noticing things and trying to understand the issue. I'm trying to understand the issue myself, as over the years I've had a few plumbers I've mentioned this too, and all they want to do is rip it out and sell me a new combi system. The heating works, its been in for years, i just don't think its working as well as it should and can see signs that its def not set up right.
I think mainly, i just need to get this pump moved to after the cold feed, I just need to work out how to get an electrical connection from the boiler up into the loft. I reckon I'm quite capable of doing that job myself (the plumbing bit), but this is why I need to try and work out if that is the correct course of action.
By the way , thank you all for your time, its very much appreciated. I'm sure its a pain in the arse trying to help someone when you cant see what i'm actually taking about.
This is why i would like to get an understanding of where this is wrong. From the diagram and what most are saying i think its definitely confirmed that the pump is in the wrong place, so that's a start. 
