direct or indirect supply water?

[BoyMeetsWorld]

Bit confused...

Terrible survey on house we're looking to buy flagged (amongst many other things) that at same time as removing / encapsulating the current asbestos cement water tank and replacing the water tanks which don't meet current insulation regs, we should switch the whole system to direct supply as it's currently indirect.

I know very little about this and assumed being indirect supply must be a terrible thing.

But googling informs me most modern houses are indirect supply and, other than being able to get drinking water from any tap in the house, there are lots of benefits to indirect - quieter system and back up if mains water goes down for starters.

Why would surveyor say we should have the whole system (water and central heating) switched to direct supply, which is obviously going to be costly esp as I doubt the pipework is in great order, and cause a lot of disruption?

Could the surveyor mean that the mains supply enters a neighbouring property and the house's supply comes off that? That could mean you can't have a water meter fitted and next door could turn off your supply.

The water that you drink should be direct off the supply. This is usually considered to be the cold tap at the kitchen sink.

Practice varies regionally. In London, older houses will have had all other taps, including the bathroom cold taps, fed from a loft tank. This has been the case for about three hundred years. In Hampshire they customarily feed cold bathroom taps from the main. This is more hygienic if you like to drink from the bathtap.

However the surveyor is more likely interested in the hot water system, and is encouraging you to have a combi boiler or an unvented hot water cylinder. You can go to this expense if you want to, but you need first to verify that the incoming water flow to the house is sufficient. Often it is not. For a start, fill a bucket at the kitchen cold tap, time it to full, calculate how many litres per minute you get. Do the same test at the utility room and garden taps, if any. Consider that a bath holds about 100 litres and estimate how long it would take to fill. There is more detail to look at afterwards.

The surveyor might just mean that the plumbing is quite old and needs renewing. Many people assume that all new boilers are combis. This is a mistake.

In plumbing terms, a hundred years is fairly old. Asbestos cement tanks are not especially old. The oldest water pipe that I know of, still in use, is about five hundred years old (at Hampton Court). In living memory, parts of the Roman system were still in use in London.

Thanks PigletJohn, it's a 60s property in Oxfordshire and yes, water comes from a tank in the loft. The survey makes the recommendation that the tanks need replacing as the current one is asbestos cement and its insulation jacket does not fit correctly . But he also states that the boiler is at the end of its useful life and recommends switching to a combi system at the same time as changing to direct supply which is where I was getting completely confused.

If he really means the insulation jacket on the loft tank, this is a trivial matter and he is wasting your time.

this one is £10.99

If he means the hot water cylinder (though it is unlikely to be the old bare copper one after all this time) £14.69 or sometimes half price as winter approaches.

I am feeling irritable and suspect that he is one of those combi-nutters.

How many baths and showers does it have, and how many people will live there?

You might not get the chance, but doing the bucket test and measuring the diameter, and noting the colour, of the incoming water supply pipe at the indoor stopcock will give some useful clues.

Assuming that the cylinder already has one or two immersion heaters, it is not urgent. Even if the boiler broke down tomorrow, you would still have hot water.

Old iron boilers are very simple and last a long time. Exactly the opposite of combis.

We rent abroad and are stuck with a combi boiler. In my house in the UK we have an oil fired range that does the heating, hot water and cooking, plus an immersion heater for hot water if the range breaks down, plus a wood burner and open fire for heat if the boiler breaks down. I like to have different options for me and the tenants. We had a new top made for our loft tank, but the original tank that was there when we bought the house remains in place.

I hate the way that the shower goes cold if someone flushes the loo or turns on a tap, as the combi cannot cope with that. Never happens in my UK house. Several people were all too keen to sell me a combi/condensing when I had to replace my range. More profit for them but less convenient for me.

Really interesting perspectives. It's very hard, knowing little about it. Yes I think he may well be a 'combi nutter' - he's also adamant we need to put a property staircase to the loft conversion, although the previous owner has actually put in very wide, solid 'safety stairs' with full bannister and staggered landing so it's not a steep descent. I do think it might be overkill. Worried if we get plumbers out they're going to fleece us, but the boiler does need replacing, the system is dirty and needs flushing and the radiators are on their last legs. There is also the issue of the asbestos cement tank.

PigletJohn - just one bathroom plus a downstairs toilet, 4 people living there but two are currently small children.

what colour is the hot-water cylinder?

When you have done the bucket test you will know more, but I suspect that incoming water flow will rather small. This can be fixed by digging a trench to the meter or main under the pavement and laying a new pipe if necessary. It is not much harder than digging the garden, unless there is a lot of concrete in the way.

Just one bathroom means it will not be as awkward as if you had two people trying to run showers or baths at the same time.

Flow is not the same as pressure.

But you haven't bought it yet, so anything could happen.

The best time to do disruptive works is before you start decorating and laying new floors.