Central Heating Only Coping With Heating 3 or 4 radiators

Mainly, because of its reliability, it has never, ever, tripped on combustion failure, hasn't required a single replacement item apart from a few service items like oil burner nozzles and door gaskets.

I understand now, I thought when writing my you were in the third person. The Profile, which I thought you were writing about, has the date of casting on the hex which would give the age.
 
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Beg, borrow or steal a mirror so you can extablish 100% which way that pump is pumping, presuming that the pump is on the boiler flow then IMO wrong IF pumping upwards, you will have to establish that as it may be pumping correctly downwards and the plumber just turned the pump head through 180 deg.
That side of the pump is so tight against the wall that I can't get a reflection. However, the plumber did admit that the problem he had with the installation was the head pointing the wrong way, and that he'd had to turn it through 180 deg. I don't think that's conclusive evidence, as I mentioned earlier he hadn't been totally confident with that install. I think all I can do is add that to the list of things to be checked that have emerged so far from this discussion. And possibly look for an informed 2nd opinion from another plumber. I'd like my original one to have a look, but as I mentioned, not returning calls.
 
Ok then, try it from another angle, at the back, might be able to determine the direction of flow.
If its pumping downwards then the "bulbous" bit is the pump inlet at the top, if pumping upwards, that bit is on the bottom.

Another way is to feel the pipework near the pump when the boiler starts up and is running, if pumping correctly, this should get hot very/fairly rapidly, if pumping upwards, this piping will be cool for a considerable time.

Or feel the cylinder coil return (bottom), if hotter than the top (flow) then pump installed incorrectly.
 

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That BritTherm pump doesn't really have a bulbous bit to it (that I can make out). But pipes going in and out are red hot, same with those either side of the two-way valves. Can't say if one pipe is hotter than another as all are too hot to leave your hand on. On a side note, my original plumber (A) is talking to me again and I've persuaded him to come in on Friday. Mainly to look at the failed Grundfos pump, and sense check what the other plumber did and has suggested.
 
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Looks as if installed correctly, when/if you feel the return pipe at the boiler, is it just cool or fairly hot because with a red hot flow temperature then the return should then get quite hot after 5/10 minutes, maybe say 15C lower than the flow temperature, if remaining cool then you a have a low flow/circulation problem.

Why is the plumber looking at the failed Grundfos pump?.
 
Why is the plumber looking at the failed Grundfos pump?
1. I believe it's under warranty
2. It didn't make the loud humming noise the BritTherm makes
3. If it can be serviced / repaired, I believe it's better quality than the BritTherm. Certainly more expensive.
4. If points 1 and 3 are true, then it can be put back in service or kept as a spare

Happy to be challenged on those points though.
 
That BritTherm pump doesn't really have a bulbous bit to it
It is not the bulbous bit , if you look closer at the pics there is a direction arrow, this is the important bit, rotating the head does not alter the direction of flow the arrow on the pump should be pointing towards the 2 x zone valves , with the flow problems you are having it is unlikey replacing the boiler will make any difference, in fact some modern boilers will actually be worse if you dont sort out the circulation/balancing problem
 
It is not the bulbous bit , if you look closer at the pics there is a direction arrow, this is the important bit, rotating the head does not alter the direction of flow the arrow on the pump should be pointing towards the 2 x zone valves , with the flow problems you are having it is unlikey replacing the boiler will make any difference, in fact some modern boilers will actually be worse if you dont sort out the circulation/balancing problem
The only way I could look at the direction arrow would be to remove the pump, which is way outside my comfort zone. But I do have that on the checklist for when the plumber comes in, alongside all the other useful tips people have been giving me here.

Which brings me onto your last point - something I suspected but good to hear from someone else. I'm not seeing or hearing any evidence that the boiler is the cause of the problem. Yes, it's old and overdue for replacement, but the circulation needs resolving first. And I definitely don't want to be adding to the problem.
 
The only way I could look at the direction arrow would be to remove the pump, which is way outside my comfort zone. But I do have that on the checklist for when the plumber comes in, alongside all the other useful tips people have been giving me here.

Which brings me onto your last point - something I suspected but good to hear from someone else. I'm not seeing or hearing any evidence that the boiler is the cause of the problem. Yes, it's old and overdue for replacement, but the circulation needs resolving first. And I definitely don't want to be adding to the problem.
If you plumber is confident and comfortable to try, ask him to temporallily remove the thermostat phial from the boiler and see if it makes any difference, if the boiler starts to kettle just switch it off and replace the phial, then the boiler is fine , if the system suddenly starts working it is the boiler thermostat that is faulty
 
If you plumber is confident and comfortable to try, ask him to temporallily remove the thermostat phial from the boiler and see if it makes any difference, if the boiler starts to kettle just switch it off and replace the phial, then the boiler is fine , if the system suddenly starts working it is the boiler thermostat that is faulty
Right - adding that to my list. My wife has been saying for weeks now that she thinks it's the thermostat, and that no-one is taking her seriously.
 
1. I believe it's under warranty
2. It didn't make the loud humming noise the BritTherm makes
3. If it can be serviced / repaired, I believe it's better quality than the BritTherm. Certainly more expensive.
4. If points 1 and 3 are true, then it can be put back in service or kept as a spare

Happy to be challenged on those points though.
If you have the Grundfos in yout possession, have a look at the arrow on that one, if the arrow is pointing down with the head right way up will means at least that that pump was installed correctly as the head would have had to be rotated through 180 deg.
 
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Did she mean the boiler control thermostat?
Any thermostat :giggle: - I think because she (and I for that matter) want the solution to be something simple that has been overlooked. Versus the probability that the house will have to be ripped apart to find (a) blocked pipe(s) somewhere.

If you have the Grundfos in yout possession, have a look at the arrow on that one, if the arrow is pointing down with the head right way up will means at least that that pump was installed correctly as the head would have had to be rotated through 180 deg.
I do, and it looks as you have described - arrow down / head right way up.
 
Probably find that pump is perfectly OK, your plumber or yourself can just remove the head and check that the impeller vanes are clear by pulling a tie wrap through them, also looks like the replacement pump is installed correctly as the pipes are roasting, one thing you might check again, when the boiler has been running for say 5 or even better 10 minutes, does the return pipe (at the boiler) feel cool or warm or fairly hot?.
 
I also see that it gives 3 outputs for your model, 17.58kw, 20.52kw and 23.45kw, this may mean that your boiler does not modulate but can be supplied to give any one of those outputs, even if configured to give 17.58kw it would cycle on/off very frequently (like my 20kw oil boiler) except that your heating/HW demands are > 17.58kw or whatever. You may have mentioned it before but does the boiler stay off for long before it refires?.
 

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