Beware the legionella police......
Combi's don't work in larger houses - still true?
- Thread starter garyo
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Beware the legionella police......
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Legionella only breeds in stagnant water, though. A combi, by definition, is water on demand?
Which some people believe includes any water that is static as it colls down in a pipe leading from a tank to a tap.
Why does the HSE recommend that the water is returned to the cylinder / calorifer no less than 50 degrees?
Bernie, king Googleer, thinks it doesn't matter
Bernie, king Googleer, thinks it doesn't matter
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Why don't you inform the readers why the HSE make that recommendation. And what about systems where there is no re-circulation.
HSE said:
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I'm not storing or circulating water.
Infrequently used shower heads are identified as a legionaries risk.
Not many people run 50c water through their shower hose and head.
The additional risk of a plate heat exchanger and 6m of pipe that's flushed out regularly with chlorinated mains water is not a big worry.
Chlorine does disperse from tap water in time in the same way that carbon dioxide disperses from your lemonade.
Infrequently used shower heads are identified as a legionaries risk.
Not many people run 50c water through their shower hose and head.
The additional risk of a plate heat exchanger and 6m of pipe that's flushed out regularly with chlorinated mains water is not a big worry.
Chlorine does disperse from tap water in time in the same way that carbon dioxide disperses from your lemonade.
H
Hot&Cold
This thread has wandered,now the current discussion is re water borne disease,ffs bernard.
The mention of varying water flow/pressure is a worry
The mention of varying water flow/pressure is a worry
The mention of varying water flow/pressure is a worry
I thought that was fairly normal? I've not quantified it other than noticing that sometimes the showers have a good day or bad day, but the way the house is piped in 15mm it could be that it's particularly sensitive to supply pressure fluctuations that are only +/- 5%.
I'll try to do a flow test on a weekday morning and compare with the last reading.
I'll offer some layman input if I may.
I was chatting to the 'good' Scottish Gas engineer who came to blow some crap out of our microbore system recently, he's the same guy I spent some time with when he power flushed it a few years ago. He's the guy you can 'talk to' rather than the first guy who came, who couldn't cure the cold rads, and recommended a new combi on interest free credit. Anyway, I was asking about having a better shower etc (along with upgrading our system) - the good guy's recommendation is that an unvented cylinder and a standard boiler is the way to go (but not an overpriced one from SG).
Some background: After living in houses with hot water tanks for donkeys years, I then lived for about 12 years in a flat with a combi. Combis can only heat one 'circuit' at any time, so if you come home freezing to a cold flat you can't run a bath and have the heating on - it's one or the other. You also can't have hot water running at a trickle, it needs to be flowing fast enough for the boiler to kick in - so you get splashed when you're rinsing the round bottomed cat food bowls etc. (plus the lag issue you mention).
Then, about 8 years ago I moved into a house with a tank again and realised how much I prefer not having the above issues. The down side is that you're heating a full tank you might not use, or, on the other hand, you might run out of hot water. He reckons modern tanks keep the water pretty hot so it wouldn't cost much to 'jag it back up to temp' if necessary, or even keep it on permanently (or often).
An unvented cylinder would give you mains pressure at your taps/shower, would take up the same space your existing unvented cylinder takes up, and would be a simpler boiler.
Hope this helps
One step further is a second coil in a vented cylinder to provide mains pressure hot water to the shower with taps being fed at lower pressure from the water stored in the tank.
The virtual cost of space in the loft ( or a couple of feet higher than the highest hot tap ) for a cold water storage tank is more than offset by not having the real costs of annual servicing an unvented cylinder.
Which is?
What ever the G3 quailified person wishes to charge
So yet again, you don't know, yet think it is worthy of criticism?
comparision by itself is not critism.
Actually you asked a question which implied that you may not know how much a G3 qualified person would charge for an annual safety check on an unvented cylinder,
I asked you if you knew how much an annual service of an unvented cylinder was.
You only ever bring it up to bang your particular drum for open vented systems.
For the record, my firm doesn't charge anything extra unless there is a problem that needs rectifying It takes minutes to do. I'm sure most reputable outfits are similar if they're also doing a boiler service at the same time.
Had to sort out far more issues so far this year on gravity systems than we have Unvented. I have seen far more of both this year so far than you have.
You only ever bring it up to bang your particular drum for open vented systems.
For the record, my firm doesn't charge anything extra unless there is a problem that needs rectifying It takes minutes to do. I'm sure most reputable outfits are similar if they're also doing a boiler service at the same time.
Had to sort out far more issues so far this year on gravity systems than we have Unvented. I have seen far more of both this year so far than you have.
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