We've bought a typical early 70's 4 bed house.
It has GFCH, open vent 'Y' system with microbore which is under the solid floor at ground level.
None of this works. The hot water doesn't get hot. I've spent some time with replacement pumps and a flushing system. Basically the boiler circuit is almost completely blocked. The flow is so slow, that the return out of the cylinder is cold, the only rad working is the bathroom, which I reckon must be plumbed directly into the primary and probably bypasses the blockage. If I turn off the bathroom rad, all that changes is the amount of kettling increases. A plumber looked at the system before we bought and expressed the opinion that the manifolds were blocked. I don't think it's worked properly for years.
Anyway, I've decided to replace the lot, the boiler is 10 yrs old non-condensing type, and I wish to install solar assistance as well. So, I've bought a new cyclinder with twin coils. The boiler coil is a 'high recovery' type. I plan to install a new boiler and the cylinder. (not me personally!)
My questions are:
1. Is there any difference in in performance and reliability between a system boiler, and separate components?
2. I guess I'll need to re-plumb the ch completely, am I right in thinking that the 30 year old microbore might be easier to replace than to try and clean out?
3. Will it be safe to re-use old radiators (I'm changing to a pressurised system) No I don't mean mains pressure - there's not a lot of that!
4. Does it make sense to allow the cylinder to run hot, say up to 60, use a TMV to distribute the hot water, and the let the temp fall to 35 before getting the boiler to fire? I have read that gas boilers work best when working hard, so thought that the bigger temp difference would be more efficient. (The cylinder has 50mm insulation)
It has GFCH, open vent 'Y' system with microbore which is under the solid floor at ground level.
None of this works. The hot water doesn't get hot. I've spent some time with replacement pumps and a flushing system. Basically the boiler circuit is almost completely blocked. The flow is so slow, that the return out of the cylinder is cold, the only rad working is the bathroom, which I reckon must be plumbed directly into the primary and probably bypasses the blockage. If I turn off the bathroom rad, all that changes is the amount of kettling increases. A plumber looked at the system before we bought and expressed the opinion that the manifolds were blocked. I don't think it's worked properly for years.
Anyway, I've decided to replace the lot, the boiler is 10 yrs old non-condensing type, and I wish to install solar assistance as well. So, I've bought a new cyclinder with twin coils. The boiler coil is a 'high recovery' type. I plan to install a new boiler and the cylinder. (not me personally!)
My questions are:
1. Is there any difference in in performance and reliability between a system boiler, and separate components?
2. I guess I'll need to re-plumb the ch completely, am I right in thinking that the 30 year old microbore might be easier to replace than to try and clean out?
3. Will it be safe to re-use old radiators (I'm changing to a pressurised system) No I don't mean mains pressure - there's not a lot of that!
4. Does it make sense to allow the cylinder to run hot, say up to 60, use a TMV to distribute the hot water, and the let the temp fall to 35 before getting the boiler to fire? I have read that gas boilers work best when working hard, so thought that the bigger temp difference would be more efficient. (The cylinder has 50mm insulation)
