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Being a Gas Safe Registered Heating Engineer by trade . I have for your delight , 3x Honeywell DT92E . wireless room stats all boxed and new .
Please note that 2 have sealed boxes , the 3 third the seal was broken by me to show you the contents .
£50.00p each . and free postage . will accept Paypal .just PM me if interested .
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i take it these wont work with the hive system?

also quick question we have a water tank in the loft (combi cold and hot tank style), when we run the bath we seem to empty the tank (bath half filled) and then have to wait for it to fill back up again before continuing (aslong as we have boost on the hive the water is still hot after the refill) is this normal for this type of tank or does that suggest the output pipe is larger than the incoming feed or a problem else where?

i assume changing the system to a combi boiler would take out the need for a tank and resolve this issue?
 

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Hello Sianderson. The reason is because you have what we know as ca "fortic " tank (ie cylinder with storage tank on top )
The cylinder can only heat the water in the cylinder . so once that's run out ( half a bath) then it introduces cold water from the tank above . so it requires heating . then you can finish off filling the bath .
There are 2 ways around it .
1 ) put a hotwater cylinder in a cupboard below loft level ( if available ) we normally go for a 36x18 indirect cylinder .
And put a 25 gallon cold water storage tank in the loft
2 ) update to a pressurised hotwater cylinder ( somthing like a 120 liter invented cylinder ) if room in the loft .
3) replace boiler for combi so no need for storage tanks .
 

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thanks i think thats the same thoughts as us, the only question i have unless ive missread it in your answer is does the cylinder wait for the level to go down and naturally be a slower refill or should it be trying to refill at the same rate as the output, we can litterally empty the cylinder of water rather than it just running cold? is this normal for this type of tank?

we have an old back boiler with an old gas fire (typical ex council place) so thinking a new boiler maybe best to "modernise" the system so we can change the fire also (when we moved in the timer controls etc was in the loft with the tank so had to use ladders everytime we wanted to change something lol, soon got british gas to put in hive for us so the theromostat controls was in a sensible place)
 

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Yes sorry . forgot to put that the hot water cylinder will empty at a faster rate than what the storage tank above it can refill . and also . the reheat time to reheat the cold water now entering the tank can sometimes be up to an hour .
But that all depends on how efficent the boiler is ( normally for a back boiler the efficentcy rating is about 75% which works out at class C to D rated ( A being the most efficient and D or E should be replaced ) not trying to spend your money . but if you can understand that with a back boiler around 10-20 % of the heat produced to heat the water or heating goes straight up the chimney. And it gets worse if you have a perminant pilot .
Where as class A rated boilers re-circulate those exhaust gases into a second heat exchanger to heat the water . and so via a zero rated gas valve it reduces the amount of gas required for the load its being asked to perform .
It reduces flue gas temperature . down to dew point (50 degrees C or there abouts so the gases now include a certain amount of condensation water .which collects in a sump incorporating a 75mm water trap .( so no products of combustion enter the building . once thecsump is full it emptys via a plastic pipe into a main drain .
So In theory what comes out the flue should be hot air mixed with water vapor .so if you ever go by a property with the boiler flue smoking with white smoke . its no more harmful than putting your face over a steaming kettle .
The only downsides are 1) they only are really condensing boilers ( class A ) when at full rate ( first thing at initial start up ) . and for about an hour Max after .once the gas valve modulates down ( starts to close dependant on load ) they become a normal everyday boiler .
2) the condense water produced is acidic . so requires treatment via main drain (4%acidity) but its been known to rot the internal casing and flue of the boiler .
3) life span approx 10 years due to the above . ( I've ripped out many a condensing boiler for that fact .
Sorry for the long reply .
 

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Average hot. Tap outlet 10 litres per minute ( mains fed - tank fed 6 )
Average fortic cold water storage tank holds 15-20 litres
Average cold water ball valve ( that feeds cold water storage tank ) allows 5 litres per minute to pass through .
Average bath requires 30-40 litres of hot water .
Average fortic tank holds 60 litres of hot water
So to fill a hot bath from a fortic tank requires at least 2x the capacity of the cold water storage tank on top of it ,plus the time to reheat the cold water that's entered the fortic cylinder .
 

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thanks youve just confirmed everything we were thinking, and that everything is working as it should its just annoying lol, the bath is a weird shape rather than a straight one so its going to take more water than normal so i guess another solution might be to look at changing the bath to a smaller one lol

just out of interest can i do any damage to the system (i.e air in the pipes if i did happen to just leave the tap on in the bath while it emptied completly other than just have cold water slowing coming out) ive always turned the tap off as soon as i see the water pressure start to drop to let it refill

feel free to spend my money, my girlfriend does enough of that lol but yes understand what you mean about the boiler it is in our plans to eventually change it, although not an official quote yet just a vague conversation with a british gas guy i think we are talking around £3k - 4k for what we want as the boiler will be moved to the kitchen (other side of the wall where it currently is), we already have a gas cooker and naturally hot water taps in the kitchen so im hoping it should be quite straight forward to fit) a new gas fire in place of the backboiler (although we may opt for a posh looking electric one so maybe discount this from the price) and to put a radiator on the same wall as where the backboiler was but further down (no other radiator in the room but there is one on back of that wall so should again should be easy? if you can just run the pipes through the wall??

does this sound a sensible price?
 
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