Hello,
We live in a 3 bed detached house - soon to be a 4 bed. The existing ten rads will probably increase to 15 rads. There are two baths and three showers. Our existing gravity fed system with a roof tank and cylinder in the airing cupboard need to go due to the airing cupboard being removed (and the fact the 30yr old glowworm boiler died about a month ago). As far as I can see there are two main options. One is install a combi, the other to install a mega flow (or similar system in the disused garage).
We have a 15mm water main coming in with a flow rate of 14 ltr/min and standing pressure of 4 bar. We've also got mains gas.
Now my concern is that a combi would vary and struggle to maintain supply to have a decent shower if someone else flushed the loo or started the dishwasher/washing machine. What has thrown me a bit is that one plumber has said that an unvented system would also struggle since it relies on mains pressure to provide the hot water. This is obviously disturbing since it seems to negate the whole point of the system. Assuming that a decent combi can provide 15-19ltr/min water - then why have a mega flow!
One other plumber has suggested that we should increase the size of our copper 15mm pipe that runs to the street (23 or 27mm I think). When I asked how this would work, i.e. wouldn't there only be a 15mm hole on the stop cock for a pipe leading to the property he seemed a little vague and said that even if that was the case, the extra storage capacity of the large pipe would still benefit us despite a possible 15mm restriction at the street.
Any and all help much appreciated. Currently we have been looking at Worcester range.
We live in a 3 bed detached house - soon to be a 4 bed. The existing ten rads will probably increase to 15 rads. There are two baths and three showers. Our existing gravity fed system with a roof tank and cylinder in the airing cupboard need to go due to the airing cupboard being removed (and the fact the 30yr old glowworm boiler died about a month ago). As far as I can see there are two main options. One is install a combi, the other to install a mega flow (or similar system in the disused garage).
We have a 15mm water main coming in with a flow rate of 14 ltr/min and standing pressure of 4 bar. We've also got mains gas.
Now my concern is that a combi would vary and struggle to maintain supply to have a decent shower if someone else flushed the loo or started the dishwasher/washing machine. What has thrown me a bit is that one plumber has said that an unvented system would also struggle since it relies on mains pressure to provide the hot water. This is obviously disturbing since it seems to negate the whole point of the system. Assuming that a decent combi can provide 15-19ltr/min water - then why have a mega flow!
One other plumber has suggested that we should increase the size of our copper 15mm pipe that runs to the street (23 or 27mm I think). When I asked how this would work, i.e. wouldn't there only be a 15mm hole on the stop cock for a pipe leading to the property he seemed a little vague and said that even if that was the case, the extra storage capacity of the large pipe would still benefit us despite a possible 15mm restriction at the street.
Any and all help much appreciated. Currently we have been looking at Worcester range.