Before the possible Combi Arrives

[lsearson]

gas

As im in a town house i have no loft so the f+e tank is in the top of my built in wardrobe on the 3rd floor, im going to do it today, but what is the best way to measure, so i go out and get a measure or is there a better or madebe easier way,

 

[gas4you]

The only exact way is to buy a flow cup, (weir guage) You let this fill with the mains flow and read off the scale what the flow rate is. For pressure you will need a water pressure gauge and put this over the end of the 15mm copper pipe.

If as I said before a milk bottle will fill in 2 or 3 secs this would point to around 15/18 l/min flow but give no pressure answer.

 

[lsearson]

going to get both a flow cup and a pressure tester, what sort of result (min) do i need from both pressure and flow

thanks

 

[gas4you]

Hard to be exact but ant pressure over 1 bar would be good and flow rate of over 15l/min would be good.

Do tests and post results here

 

[lsearson]

hi

i managed to get a pressure tester, but no flow cup, i do know where to get one from so will pick that up next week,

i only just put the mains tester on the garden tap so far which is a very short tee off the kitchen tap and the reading is 4.5bar, which surprises me, if that is the case do i need to do any further testing as if i loose 0.25 bar per floor i should have at least 3 bar on floor 3.

 

[gas4you]

4.5 bar is very good and I would have no problems with fitting a combi on this for a 3 storey house. It is always best to check flow rate as the 4.5 is only a standing pressure. Try turning on another cold tap whilst pressure guage is connected and see what result you get then

Don't forget that all advice on here is general advice. Only a competent person on site can give you a 100% accurate answer

 

[Agile]

hi

i only just put the mains tester on the garden tap so far which is a very short tee off the kitchen tap and the reading is 4.5bar, which surprises me, if that is the case do i need to do any further testing as if i loose 0.25 bar per floor i should have at least 3 bar on floor 3.

Its a simple fact that a combi relies on the mains water supply for delivering hot water. You need at least 20 li/min open pipe.

If its insufficient then you will have wasted you money on a boiler you cannot use.

If you were paying for all this free professional advice then would you then still want to ignore it?

You dont need a flow cup to measure the flow. Just find a saucepan or bucket of known volume or measure the volume by filling it with a measuring jug. Then measure seconds to fill it.

Just because gas4u is not concerned that does not mean that you should not be either. Remember he is not losing out if YOU find you have wasted £1000 on a boiler you dont have flow rate for!

My mother had a pressure ( static ) of 3 Bar but an open pipe flow of only 4 li/min. It was at the end of about 0.5 kM of 1/2" pipe.

As you have a pressure gauge then measure the flow rate you can achieve with a ( dynamic ) pressure of 1 Bar on your gauge.

Tony

 

[gas4you]

hi

i only just put the mains tester on the garden tap so far which is a very short tee off the kitchen tap and the reading is 4.5bar, which surprises me, if that is the case do i need to do any further testing as if i loose 0.25 bar per floor i should have at least 3 bar on floor 3.

Its a simple fact that a combi relies on the mains water supply for delivering hot water. You need at least 20 li/min open pipe.

If its insufficient then you will have wasted you money on a boiler you cannot use.

If you were paying for all this free professional advice then would you then still want to ignore it?

You dont need a flow cup to measure the flow. Just find a saucepan or bucket of known volume or measure the volume by filling it with a measuring jug. Then measure seconds to fill it.

Just because gas4u is not concerned that does not mean that you should not be either. Remember he is not losing out if YOU find you have wasted £1000 on a boiler you dont have flow rate for!

My mother had a pressure ( static ) of 3 Bar but an open pipe flow of only 4 li/min. It was at the end of about 0.5 kM of 1/2" pipe.

As you have a pressure gauge then measure the flow rate you can achieve with a ( dynamic ) pressure of 1 Bar on your gauge.

Tony

what a load of s***. where does your mother live with with 0.5km of pipe, Buckingham Palace. if it is this long then it has been installed under sized or do you not know this

Where in my posts have I not told op to check flow and pressures all the time What citeria dose op use for filling saucepan or bucket. What size bucket or pan How long to fill I am now begining to understand others respones to your replies. Perhaps they are right you should stick to repairs

 

[lsearson]

i have measured the pressure and flow, so here goes

i have static pressure of 4 bar, and a flow rate of 14.5 litres per min open pipe on the 3rd floor coming from a 15mm pipe.

i have looked at the vaillant ecotec plus 37kw combi boiler for this house,

any ideas

 

[gas4you]

Very good boilers. It will let you get very drop of hot water available to your taps/shower. You will need to have you gas pipe sized correctly to ensure enough flow of gas from meter to boiler

My concern is that 837 will give 14.5 lires of hot water max @ 35C temp rise at ground floor. I am wondering how much this will drop by the time it reaches 3rd floor?

What is your flow rate from cold tap on ground floor? Is it greater than 3rd floor?

perhaps one of the other plumbers on here can give more accurate info on pressure/flow drop over 3 floors?

 

[kevplumb]

1 bar =30m head approx

 

[gas4you]

Thanks kev. At last someone with some useful input

 

[Agile]

what a load of s***. where does your mother live with with 0.5km of pipe, Buckingham Palace. if it is this long then it has been installed under sized or do you not know this

I dont understand why you think it necessary to make such a rude and agressive posting. As it was on a Saturday evening I hope that you were drunk and acting out of character.

This is in the countryside on the edge of a village in Cornwall. The house was supplied from a well but they decided to have the mains water main added when mains water was extended along the lane. Someone laid the 1/2" pipe from the lane to the house about 30 years ago and obviously it was undersized but much of the problem may be because the number of houses on the lane has doubled and old ones been uprated so its probably quite inadequate even at the lane 0.5 km away.

The house was built in 1931 with a flat roof and had a large steel tank with a float valve only half way up. The rain water from the roof went into the tank and if the level fell below the valve then the pumped well filled it halfway. The pumped well was disconnected when the mains water became available.

Tony

 

[lsearson]

i have measured the flowrate now from the kitchen tap, and that delivers a good 21 litres per minute so a lot greater than the 14.5 letres per minute i get on the 3rd floor

ive also checked my gas pipes and they are 3/4"

 

[kevplumb]

I dont understand why you think it necessary to make such a rude and agressive posting.

for the same reason the rest of the regulars don't understand why you have to such a pompus, condesending git