Issues with plumbing in an old bungalow

[Naz1977]

ok, so have a 1930s bungalow which bought about a year ago. Going through some building work at the moment and with the ceilings off, it is best time to take a look at the plumbing.

About 3 yrs ago the boiler ( conventional type with hot water cylinder in the roof void) got replaced by a combi boiler ( Worcester Bosch 30Si I think ). But the water pressure is not good at all. When one cold water is running, others almost come to a drible. I know with the combi you get pressure issues, but I thought this was only for hot water and not cold ?

Looking at some of the pipe work, it seems that when they did the boiler, they just chopped and shaped and cut the pipes to whatever they needed without thinking about anything else.

So gonna be ripping out all the pipes and redo them in the proper organised way.

Questions I have:

1) Seems the main cold feed that goes in to the boiler and also Ts to the kitchen tap is 15mm. Is this normal?

2) The CH pipes coming out the boiler are 22mm but somewhere they get reduced to 15mm before going out to the rads. Again is this normal ?

3) there seems to be multiple stop cocks around the house and around the main feed coming in. I can see 1 outside before getting to the meter. THen I can see 2 more inside. BUt can't see what they are for as they are behind a kitchen unit. Will be ripping the unit out to see the pipe work. Again is this normal?

4) To make the pressure better, I am thinking about running 22mm pipes everywhere and then reduce to 15mm just before they go into taps/sinks and ... , is this ok to be done?

Thanks for all the advice.

 

[flameport]

1 - yes, most older properties and plenty of new ones have 15mm or equivalent.
2 - No, although it does depend on how many and the size of the radiators.
3 - Ideally you want one internal which will shut off the cold supply to everything. Clearly labelled and accessible.
4 - You can do it, but it may not have much or any effect. For hot, it will significantly increase the amount of waste and the time taken for hot to reach the outlets.
Pressure is what you get from the water supply - if it's low there is little you can do about it other than have a new supply installed.
Flow on the other hand can be affected greatly by the pipes and fixtures, it only needs one partly closed valve or a blocked/crushed pipe to reduce the flow significantly.

Before making any decisions, you need to find out what the pressure and flow from the cold supply actually is - at the point it enters the property.

 

[Naz1977]

Thanks.

As regards to hot water pressure: If the incoming pressure is low, does it also effect the hot water pressure? Or is the hot water pressure supplied by the boiler?

How can I get the pressure tested? Is it something that a plumber can only do? Obviously I can measure the water pressure in the bath for example, but that could be limited by poor taps or pipe work?

 

[Newboy]

Are you confusing flow with pressure? Low flow and low pressure are different issues.

Your hot water pressure will be limited by your incoming mains pressure and the flow rate will be limited by the combi-boiler.

If you want to measure your incoming pressure (static) and you have a stopcock then http://www.screwfix.com/p/monument-tools-mains-water-pressure-test-gauge/82412

 

[Naz1977]

Are you confusing flow with pressure? Low flow and low pressure are different issues.

Your hot water pressure will be limited by your incoming mains pressure and the flow rate will be limited by the combi-boiler.

If you want to measure your incoming pressure (static) and you have a stopcock then http://www.screwfix.com/p/monument-tools-mains-water-pressure-test-gauge/82412

ah, thought they were related to each other.

The tool you have listed says it is for washing machine only as it has a bsp on it. I will see what connection I have after my meter/stopcock and see if that would work. But didn't want to measure at the washing machine as by then it has gone through some of the pipe work and might be restricted?

 

[Newboy]

You can still measure the static pressure at the washing machine outlet or at a garden tap (BSP thread on the spout) - static pressure will be be the same at all mains outlet points.

1) The pressure at the point where your supply pipe connects to the main is reasonably constant - it does vary during the course of the day as demand for water changes (slightly higher overnight when demand is low and lower in peak demand periods)

2) If you have a restricted service pipe to your property then

a) The static pressure will not change
b) The flow rate will be comparatively low
c) The dynamic pressure will be low - due to the restriction, the amount of water that can flow through the pipe is limited.

If you want to measure the static/dynamic pressure at various outlets then try this
http://www.screwfix.com/p/rothenberger-water-pressure-gauge-10bar/8991k#_=p

 

[dilalio]

Ask your supplier to come out and measure the flow and pressure at their side of the incoming main.

This will tell you if performance is restricted by pipework on your side or if that's all your going to get!

If they measure something like 3bar and 20 litres per minute (or upwards of that) then you can do something your side to get the most out of what's being delivered... this will fluctuate according to demand.

 

[Naz1977]

Thank you for the info. Do the suppliers come out easily to issues like this ? or do they take ages to action?

 

[dilalio]

Your guess is as good as mine!