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combi boiler

Tankless water heaters — also called instantaneous, continuous flow, inline, flash, on-demand, or instant-on water heaters — are water heaters that instantly heat water as it flows through the device, and do not retain any water internally except for what is in the heat exchanger coil. Copper heat exchangers are preferred in these units because of their high thermal conductivity and ease of fabrication.
Tankless heaters may be installed throughout a household at more than one point-of-use (POU), far from or without a central water heater, or larger centralized whole house models may still be used to provide all the hot water requirements for an entire house. The main advantages of tankless water heaters are a plentiful, practically limitless continuous flow of hot water (as compared to a limited flow of continuously heated hot water from conventional tank water heaters), and potential energy savings under some conditions due to the use of energy only when in use, and the elimination of standby energy losses since there is no hot water tank. The main disadvantage of these systems are their high initial costs (equipment and installation).

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  1. H

    Pipework changes needed to replace a conventional boiler to a combi ?

    What pipework changes are needed to replace a conventional open vented gravity boiler to a combi boiler ? Would toilet flush/cisterns need replacing ?
  2. M

    Combi boiler hot water but no heating

    My first thought when I heard this fault a combi boiler with hot water but no heating. Was a problem with the stat, controls not making the call for heat. If this is not the case. Can the divertor valve be the cause of the issue?
  3. B

    Combi Boiler pressure refill?

    Hi, Just had a "Main Eco Compact" combi boiler installed as the Biasi one failed. It seems to work fine, gives a hot bath, i dont ever use the radiators or kitchen hot tap. (no point in upping the landlords gas bill for no reason) On day 4, the pressure is below 1. I filled it back up to >1, but...
  4. T

    Replace electric boiler &hot water storage tank 4 Electric CombiBoiler

    Is it worth replacing a Potterton gold 9kw electric boiler with a hot water storage tank for a new Electric Combi Boiler ? Would there a reduction is electric consumption and therefore a saving ? Please advise
  5. D

    Ideal logic combi boiler with mechanical timer swap with electrical

    Hi all, i moved recently in new home and realised that there is no room external thermostat wired to the Ideal Combi boiler. There is only mechanical timer on it. I saw some videos on Internet that mechanical timer can be replaced with electrical one but i am not sure if it is compatible with...
  6. P

    Combi boiler: my hot water has started running lukewarm.

    I have a Combi boiler and, a few minutes ago I turned on the hot tap in the kitchen and the water was far from hot. In fact, it was decidedly lukewarm. I checked the boiler and the tap icon was lit up, showing it was delivering hot water to the taps and I could hear the boiler running and the...
  7. A

    Combi Boiler Install in Devon, Exeter.

    Hi, I recently fitted a new central heating circuit and ran hot and cold to the bathroom and kitchen in my property (I was a CORGI registered central heating installer about 15 years ago, so I felt comfortable running the flow/return to rads). I am in need of a combi boiler install with a...
  8. N

    Combi boiler install doesn't seem quite right.

    I've just had a back boiler removed and combi boiler installed and have noticed that my radiators are heating up when using the hot water. I've been told this is due to the residual heat being moved around the system once the hot water is satisfied. But the radiators are heating up as soon as i...
  9. I

    Water Softener advice now I've moved to combi boiler

    Hi, We have a Kinetico 2020c HE Water Softener, fitted in 2008 in our loft to the cold water tank in a vented system with a conventional boiler. All good, was working fine. Recently our old Potterton Suprima conventional boiler packed up and we decided to change to a Vaillant EcoTec COMBI...
  10. F

    Oil Combi Boiler Hot/Cold/Hot

    Hello. I have an oil fuelled combi boiler and the hot water starts hot, then goes cold for a few seconds and then back to hot... Is this right? Thank you.
  11. A

    Heatline combi boiler

    I have a heatline vizo 24 combi boiler that starts up for a few seconds and then shuts off. This happens with both hot water and heating. If left all overnight or all day it will work first time and stay on. If tried again soon after the problem comes back.
  12. J

    Combi boiler obsolete part dilemma

    Hi everyone, I have been searching the Web for a spare part for a Worcester 35 cdi ng boiler that is obsolete. I can't find one anywhere and its looking more and more likely I'm doomed . The part is the door extrusion seal 87161031280. I have sold my house STC and this has just happened , so...
  13. W

    Combi boiler - bang when hot water opened

    Hi All! I hope you can give me some advise. I had combi boiler (Viessman vitodens 100-w 30kW) installed about half year ago. Recently I start hearing one single bang when hot water is opened at any of taps around house. It sound like someone in other room will knock a radiator (not relly loud...
  14. M

    Shock arrester combi boiler

    I usually fit these on the cold feed to the boiler close to the boiler. But if fitting near the boiler would be unsightly. Would they still be effective fit somewhere else in the cold.feed in the system. Say under the kitchen sink? Thanks
  15. G

    combi boiler system draindown problem

    during drain down of system with all trc open and bleed valves open water just continues to drain out and boiler pressure remains at 1.5bar.Baxi combi boiler 105
  16. J

    Gloworm combi boiler help!!!

    Some advice would be very much appreciated. Our Gloworm Ultracom 38CXI combi boiler recently developed a few issues. Recently some our taps/shower but not all of them will run hot initially and then run cold after around 2 minutes of running hot. The heat exchanger was replaced by our...
  17. computermike

    Pipes in concrete floor with combi boiler

    I am looking to replace an oldish boiler and hot tank with a combi boiler. The house dates from around 1968 and quite possibly the (copper) piping could be that old. I had someone round to give a quote and they said they would not recommend a combi boiler because the piping downstairs was buried...
  18. A

    Can a council tenant have any say in where a new boiler is situated?

    The council are offering to update the fire and inefficient old radiators and replace the old fashioned boiler with a new combi one. They want to move the boiler from the tank cupboard in the bedroom to the much bigger walk-in wardrobe, presumably for convenience as there seems to be a gas pipe...
  19. J

    Combi boiler keeps locking out

    Hi everyone. I was hoping someone here might be able to help me with a problem I have. After using our shower for around five minutes it seems to be causing the boiler to lock out. It’s a thermostatic mixer shower running from a Worcester Greenstar 30si combi boiler. Weirdly, this only seems...
  20. S

    Need to renew 17yr old combi boiler.

    Renewing 17yr old Gloworm combi boiler, running dom h/w and 15 rads, 40% are doubles. Water flow from stop valve has been measured as 6L p/m, is that enough to run system effectively?
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