Secondary return or trace heating tape?

Section62

grumbler said:

Well, my informal obligations are probably more valuable than 'legal' ones that pretty often are very difficult or even impossible to enforce.

It is very easy not to pay a trader after they've completed a job.

What I mean is Bendy wouldn't be able to productively advise someone you did a favour for to contact their LP with a view to taking action against you.  On the other hand, a trader has to work in accordance with the norms of the industry, or be able to justify why they've done something different.  Running HW supplies to the kitchen using microbore pipe is not an industry norm.  But may well be a sensible solution in the OP's case.

We can be more flexible about what we do in our own homes or as DIYers. Traders have to be more constrained, which shouldn't be seen as a negative attribute.

Apodemus

Bendy_House said:

grumbler said:

You hardly ever need a really big flow of hot water anywhere except a bath and a shower. I helped my friend to run separate 10mm pipes instead of 15mm to the sink and to the basin - and his wife was happy with the result despite being sceptical first.  This more than halves the time needed for hot water to reach the sink and the basin.

Anyhoo, since folk are seemingly 'happy' to accept energy losses of 80W per hour or whatever, the cheapest installation solution is to attach a wee paper indicator flag to the hot kitchen handle. Set to the position that'll leave the tap constantly running at a steady drip.

I think certain members of my family have been conducting an informal trial of this technique for the last 20 years or so!  

plumb1_2

Iam working in a block of modern flats at the moment, 1st 2 floors the whb and toilet in bathroom and en-suite are piped up in 10mm plastic, hot and cold.
The next 3 floors above are are 15mm, wonder why ?

Bendy_House

Section62 said:

grumbler said:

Well, my informal obligations are probably more valuable than 'legal' ones that pretty often are very difficult or even impossible to enforce.

It is very easy not to pay a trader after they've completed a job.

What I mean is Bendy wouldn't be able to productively advise someone you did a favour for to contact their LP with a view to taking action against you.  On the other hand, a trader has to work in accordance with the norms of the industry, or be able to justify why they've done something different.  Running HW supplies to the kitchen using microbore pipe is not an industry norm.  But may well be a sensible solution in the OP's case.

We can be more flexible about what we do in our own homes or as DIYers. Traders have to be more constrained, which shouldn't be seen as a negative attribute.

You are not implying that Bendy would insist a plumber do this task, against their better judgement, and on pain of having action taken against them if it subsequently doesn't work, are you?

Of course not.

And I wouldn't 'go there' with a plumber. They, themselves, would have to give it a ponder, hopefully accompanied by sage nods of the head and gentle rubs of the chin, before finally deeming it a 'goer' - and with the additional proviso that if it doesn't work, then tough on Bendy.

When I referred to 'old school' and whether a plumber would be happy to do this, it was on the basis that the plumbers themselves are well-informed enough to make a good judgement on its likelihood of success. Some - possibly many, possibly even the vast majority - will just not entertain it, as it offends their plumbing principles - they only do stuff the 'right way'; "No! It won't work! Why do you think pipes are yay big?" and even throw out a patronising sneer at the layman for their patent stupidity in suggesting it. Without being patronising to plumbers on here - thankfully we appear to have the cream - I can state with some confidence that I understand the difference betwixt, say, pressure and flow than do many professionals.

What do we have in Chickie's situation? (a) a very healthy 3+ bar (already calmed by a PRV) supply, (b) a loft-located unvented cylinder - so it'll be supplied almost certainly by a 22mm mains feed at a lovely pressure with little loss, and (c) a downwards supply to the kitchen in 8 or 10mm, so very little subsequent loss due to friction.

As a non-betting fellow, I'd happily wager, ooh, £50 that this would work like a dream. And, as I also suggested, for £25 you could first confirm this by connecting the 10m length of that pipe as a test-run.

Sheeeesh.

Bendy_House

plumb1_2 said:

Iam working in a block of modern flats at the moment, 1st 2 floors the whb and toilet in bathroom and en-suite are piped up in 10mm plastic, hot and cold.
The next 3 floors above are are 15mm, wonder why ?

To counter gravity?

Bendy_House

Chickereeeee said:

fenwick458 said:

I had a similar problem in my house, the combi is getting old (15years?) and is never really fast to generate hot water at the kitchen sink at the best of times, but sometimes it seems to fire up, just as the water is getting warm after 1 minute it'd go stone cold for 1 minute, then start burning gas again and heat it up. Maybe someone could offer a diagnosis of it? used to do it rarely, maybe 10% of the time but it was really annoying and it seems like such a waste having to run off all that water
anyway, my solution was to install an instant hot water tap in the kitchen, I got a Qettle and that seems to have solved the problem for now. according to this review , and adjusting for todays prices it costs just over 6p per day to run it in standby mode
the 90W trace heater would be in the region of 70p per day

Re the hot tap idea: I have only really seen taps that do boiling water (and cold filtered)', in addition to normal hot/cold feed. I.e. they can replace a kettle. For most kitchen purposes, you want hot, but not boiling water, and these don't seem to offer that.

Good point.

You can get small 'instant' water heaters that fit inside a base unit, and I think some come with a small reservoir. Whether these can be turned down to ~65oC I don't know.

Tbh, I wouldn't go for that option, but then I wouldn't worry too much about the water delay either. I've just turned off the pre-heat function on my combi, as the darned thing fired up every few minutes - stupid amount of wear on the parts, as well as a waste of gas. Yes, it now takes, I dunno, a good 30+ seconds to get hot through to the kitchen, but that's a price I'm happy to pay.

I think, tho', that Grumb has absolutely cracked this problem. I am almost certain it will work, and it can be tested beforehand to prove it.

If you have a mains cold in your loft (or whenever it is installed), it can be connected to a 10 (or even 8!)mm pipe, 10m long, and heading downstairs (to kitchen level), with a bucket at the end. Count the 'litres-per-minute', and you'll have your answer.

Once fitted, it'll have zero running or maintenance costs.

grumbler

Bendy_House said:

Chickereeeee said:

fenwick458 said:

I had a similar problem in my house, the combi is getting old (15years?) and is never really fast to generate hot water at the kitchen sink at the best of times, but sometimes it seems to fire up, just as the water is getting warm after 1 minute it'd go stone cold for 1 minute, then start burning gas again and heat it up. Maybe someone could offer a diagnosis of it? used to do it rarely, maybe 10% of the time but it was really annoying and it seems like such a waste having to run off all that water
anyway, my solution was to install an instant hot water tap in the kitchen, I got a Qettle and that seems to have solved the problem for now. according to this review , and adjusting for todays prices it costs just over 6p per day to run it in standby mode
the 90W trace heater would be in the region of 70p per day

Re the hot tap idea: I have only really seen taps that do boiling water (and cold filtered)', in addition to normal hot/cold feed. I.e. they can replace a kettle. For most kitchen purposes, you want hot, but not boiling water, and these don't seem to offer that.

Good point.

You can get small 'instant' water heaters that fit inside a base unit, and I think some come with a small reservoir. Whether these can be turned down to ~65oC I don't know.

I checked, the smallest reservoir seems to b 6L. Yes, they have thermostats, some even easily adjustable, but I think it's still expensive to maintain the temperature of 6L of hot water 24/7. You can't expect decent insulation from a small device.

This looks interesting, but I'm not sure how it will work  with hot water supply.

travis-powers

My wife is a hairdresser and I had to fit a online water heater to her new shop can’t say they are impressive I had to add a pressure reducing valve to get decent heat.

Apodemus

grumbler said:

Bendy_House said:

Chickereeeee said:

fenwick458 said:

I had a similar problem in my house, the combi is getting old (15years?) and is never really fast to generate hot water at the kitchen sink at the best of times, but sometimes it seems to fire up, just as the water is getting warm after 1 minute it'd go stone cold for 1 minute, then start burning gas again and heat it up. Maybe someone could offer a diagnosis of it? used to do it rarely, maybe 10% of the time but it was really annoying and it seems like such a waste having to run off all that water
anyway, my solution was to install an instant hot water tap in the kitchen, I got a Qettle and that seems to have solved the problem for now. according to this review , and adjusting for todays prices it costs just over 6p per day to run it in standby mode
the 90W trace heater would be in the region of 70p per day

Re the hot tap idea: I have only really seen taps that do boiling water (and cold filtered)', in addition to normal hot/cold feed. I.e. they can replace a kettle. For most kitchen purposes, you want hot, but not boiling water, and these don't seem to offer that.

Good point.

You can get small 'instant' water heaters that fit inside a base unit, and I think some come with a small reservoir. Whether these can be turned down to ~65oC I don't know.

Heavens!  Is that last installation designed to give you a "hot flush"...?!

Chickereeeee

Re: the 80/90w for the trace heating tape, I may have underestimated the annual cost, but it would probably only need to be on 3-4 hours per day (main food prep an clear-up times).

(Incidently, I have read that the secondary return approach disturbs the stratification of a cylinder when used in an air-sourced heat pump installation (due to lower temperatures involved) and so trace heating tape might be preferred. (not my situation now, but may be forced into it in the future)

Thanks for all considered replies.