Hot water speed long pipe run..

[adwt2004]

Hi,

I have an issue with my hot water from a hot water tank. I plan on ripping this out and having a combi fitted in it's place. The tank leaks.. and I want central heating.

The query I have is that hot water to my kitchen tap takes at least 40 secs to come through. I have measured the rough distance ( i can remember the old pipe runs from when my boards were up) and it works out at about 36 feet of pipe to my kitchen tap. Will a combi speed this time up or will I have to put the boiler somewhere closer such as in the kitchen and re-plumb? My kitchen and bathroom are above each other. It seems an incredible waste of water at present just to get some hot water. Any advice?

Andy

 

[Softus]

Why not just replace the leaking cylinder?

As for your other questions...

What type of boiler do you have?
Where is it?
Where is the cylinder?
Is it lagged?
Is the hot pipework lagged?
What gauge is it?
How old is it all?
Do you live in a hard water area?
Do you have a cylinder thermostat?
What is it set to?
How many hours per day is the hot water being heated?
Can you think of any information about your system that might be useful?

 

[sooey]

Fitting a combi may reduce the waiting time for hot water to come through a little, because it will be under mains pressure. But like you've already guessed, to reduce it significantly you would need to move the heat source (combi or whatever) closer to the outlet. That will save having to wait while all that cold water in the pipe between the heat source and the outlet runs to waste.

 

[sime10]

Whatever you do you will still waste water waiting for it to get hot to the tap

 

[Softus]

I don't agree, on two counts:

1. Less heat will be lost if everything is adequately lagged for whatever gauge of pipework is installed.

2. If the distance and inconvenience justified it, a secondary loop can be installed. This would be cheaper than converting to a combi system.

 

[sime10]

I don't agree, on two counts:

1. Less heat will be lost if everything is adequately lagged for whatever gauge of pipework is installed.


Granted but if the water wasn't run overnight you would still get the same waste.

2. If the distance and inconvenience justified it, a secondary loop can be installed. This would be cheaper than converting to a combi system.

Yep secondary loop would be ok but how many do you see in a normal domestic dwelling?

 

[Softus]

Granted but if the water wasn't run overnight you would still get the same waste.

That's right - once per day the water would start off stone cold, and the rest of the day it wouldn't.

secondary loop would be ok but how many do you see in a normal domestic dwelling?

More than zero, but what's that got to do with anything? When it's the right solution for reason of cost and convenience then it doesn't matter how many other people have one.

 

[adwt2004]

At present i just have a rectangle shaped old copper tank, i said cylinder earlier but that is incorrect. The tank has no insulation (no space for it) There is also no space to replace with a cylinder. Would have to go in loft but not sure loft could support it plus increased length of pipe run. None of my pipework is lagged. As for age I would say when this house was built, 60's... twice my age!

I changed the thermostat and added a timer and that's about it.

It does look like things will need to be moved. My missus didn't want a combi on show so wanted to put into the space where tank was. so that was obvious choice, but not happy with waiting times for hot water, I would feel very wasteful pouring all the residual cold down the drain. I could lag pipes but that won't keep water piping hot and I'll still have a 40 + sec wait the first time i use taps. Any other options? Secondary loop?

 

[sooey]

Softus the man has already stated that he wants to have a combi fitted, his choice and perfectly ok in certain situations. Lagging the distribution pipe between a combi and the outlets can't do any harm, fair enough. But do you think that fitting a secondary circulation loop could really be justified in say a normal sized house.

 

[sime10]

I still say there is still a waste of water with either method

A secondary loop is the best idea so yes I would go for that except the gas that is used heating up that extra circuit will use more energy than wasting a litre or two of water Gas is running out so why use it to heat that secondary circuit when it is not in use through the day.

 

[Softus]

Softus the man has already stated that he wants to have a combi fitted

Oh really? I thought I'd read this:

I plan on ripping this out and having a combi fitted in it's place.

...and this:

Any advice?

There's no obvious reason for your objection to the advice that I'm offering him, since it doesn't conflict with yours, so please continue with your advice and let me continue with mine.

Lagging the distribution pipe between a combi and the outlets can't do any harm

I already knew that.

But do you think that fitting a secondary circulation loop could really be justified in say a normal sized house.

Cost of installation - maybe 10 metres of pipework, some fittings and lagging, an Essex flange, one UPS 10-50, perhaps a day's work. Yup - pretty straightforward and hugely cheaper than a new boiler, let alone conversion to a combi and replacing any components that can't cope with the higher pressure. In what way is that difficult to justify?

sime10 - it's not usual to keep a secondary loop running all day long, unless hot water is liable to be in demand all day long, in which case it can result in a saving of energy.

I never said or implied that you can entirely avoid wasting water, whatever the distribution scheme. We're just discussing options and making the OP aware of the pros and cons.

 

[sime10]

Not very often a domestic dwelling has hot water being used all day long And if it was to happen Gas or oil fuel will still cost more than running of a few litres of water.

That rain is falling onto my consevatory, Can't hear any gas being wasted though

Gas is running out oil is too water is falling from the sky it costs but will never run out

 

[sooey]

Softus I wasn't objecting to your advice I thought that you were disagreeing with mine, anyway that doesn't matter, I would say though that apart from the cost of installation of a secondary loop with suitable pump, there's always the ongoing cost of running the pump and the heatloss through the secondary pipework to consider, even with insulation. that's why I asked (honest question)if you thought such a thing would be worthwhile in a normal sized house.

 

[sime10]

Gas is running out oil is too, water is falling from the sky it costs but will never run out

 

[sooey]

sime10 the water may never run out as you say, but its still a waste to heat it before pouring it down the drain. Thats what i thought the point of this thread was anyway.