Hot water cylinder help

MSaxp

Hi,

Just bought a house and when I tried the hot water, I am less than impressed.

First of all, the hot water cylinder (Range Tribune HE) seems to have water dripping non-stop through a pipe and a funnel (which seems to be called an acetal tundish!). Not sure about the point of this but i dont think that having water run non stop makes sense.

On top of that, the cylinder has a filling loop (which I suppose it meant to add pressure to the system) and as i turn both valves on, the pressure in a gauge goes up. Not sure what the appropriate pressure is though. Seems to be between 3-4bar now.

The biggest problem is obviously what you see in the taps. Turning the water heating control to on, the boiler doesnt light up. Which to me would indicate that the water is already hot. On opening the hot water tap (in the family bathroom which is next to the hot water cylinder), it seems to take minutes for any hot water to appear, and the water starts freezing cold.

I only had limited time in the new house and havent moved in yet, so will re-test today but i am slightly worried.

Any thoughts? thanks for taking the time to read this. Apologies for the deficit of plumbing vocabulary. I am, as is obvious, not a native speaker.

macman

If you have DHW stored in a cylinder, then turning on the hot tap will not fire the boiler anyway-that would only happen with a combi system.
Presumably when you bought the house there was a description of the DHW and CH systems? The Range Tribune is an unvented cylinder (at mains pressure). This is potentially dangerous, so don't play about with it before reading the manual properly. That should tell you the correct operating pressure.
Is the cylinder linked to a boiler, or does it incorporate an immersion heater?

matelodave

The purpose of the tundish is to let you know that there is a problem by showing the water flowing through it. It should never be covered or hidden away

If you've got water dripping or flowing into the tundish it shows that the pressure relief valve is leaking because the system pressure is too high (or that the relief valve is faulty).
Generally a pressurised hotwater system should be set to about 1-1.5 bar with a pressure vessel set to about 2.5 bar and a safety relief valve set to 3 bar so if yours is at 3-4 bar you should have it checked immediately by someone qualified to work on pressurised systems.

Do not fiddle with the filling loop if you don't know what you are doing as the mains pressure can be significantly higher than the safe working limits of your system. get someone in to sort out the problems and make sure they explain how the system works and when you need to adjust the pressures etc.

MSaxp

thanks for your response.

I dont really know (I am not there now). Next to the cylinder there seem to be 2 fused switches. Oddly, one is for the boiler, which is downstairs. Not sure what the other one is for. I havent found any reference to an immersion heater in the property specifics, but no manual was provided. I guess I could just run the taps and see if the boiler ever fires.

I have downloaded the user instructions from the Range website but they are not that useful. Effectively, the cylinder is just meant to work and if not, you are meant to call the plumber.

I would suppose that water running through the tundish, implies one of the 2 valves next to it is leaking.

As for the pressure, while i can see a list of operating pressures for the cylinder, I am not sure what pressure the filling loop regulates. It looks like the gauge on the expansion vessel is the one moving when i turn the filling loop on.

I will try and post a photo

MSaxp

Lets try this:
http://s1373.photobucket.com/user/MSachp/media/Mobile Uploads/IMG_20140302_154920_zpsmilvr4pk.jpg.html
http://s1373.photobucket.com/user/MSachp/media/Mobile Uploads/IMG_20140302_154913_zpstfdc4cb9.jpg.html

macman

Looks like the unvented cylinder is fed from the boiler. As would be expected.

matelodave

The grey thing under the yellow shut off valve is a pressure reducing valve to limit the pressure of the incoming water supply. The things with red knobs on the end are the safety relief valves designed to vent off in the case of overpressure in the heating & hotwater circuits. The filling loop is to pressurise your heating system circuit. I'd guess that the pressure gauge is showing your heating system pressure as it's connected to the red pressure vessel. The silver pressure vessel is for the hot water supply and allows foe expansion of the water in the hot water tank.
It actually looks a bit home made and I would strongly advise you to get someone in to check it over and make sure it's OK, especially if you've got water flowing or dripping through the tundish

ollski

The pressure gauge is for the heating, there is unlikely to be one for the hot water. It probably just needs the expansion vessel recharging and probably the 5/6 bar prv cleaning off.

Lgas

The water running constantly through the tundish, it's cold I take it? When the pressure reducing valve is faulty it does this. Your pressure is too high, and as ollski said the expansion vessel (red one) will need re-charging. The pressure should be around 1-1.5, where the indicator is (the red needle on the gauge). You need to get this looked at by a gas safe registered engineer, these are not to be messed around with.

The delay in getting the hot water to the tap will be the 'dead leg' of cold water already in the pipes, that has to come through before the hot can come through. The canister with the yellow top is a scale reducer on your cold mains pipe. It would appear that you have an immersion, do you have something with a cable coming out at the bottom of the cylinder that goes into the wall? One switch may be for your boiler and controls (usually the one with the removable fuse) and the other probably for the immersion heater (keep this turned off, costs a lot to run).

MSaxp

Lgas wrote: »

The water running constantly through the tundish, it's cold I take it? When the pressure reducing valve is faulty it does this. Your pressure is too high, and as ollski said the expansion vessel (red one) will need re-charging. The pressure should be around 1-1.5, where the indicator is (the red needle on the gauge). You need to get this looked at by a gas safe registered engineer, these are not to be messed around with.

The delay in getting the hot water to the tap will be the 'dead leg' of cold water already in the pipes, that has to come through before the hot can come through. The canister with the yellow top is a scale reducer on your cold mains pipe. It would appear that you have an immersion, do you have something with a cable coming out at the bottom of the cylinder that goes into the wall? One switch may be for your boiler and controls (usually the one with the removable fuse) and the other probably for the immersion heater (keep this turned off, costs a lot to run).

Yes, the water flowing through the tundish is cold.

As is the water in the taps, unfortunately. I can get lukewarm but not properly hot.

Not sure about the immersion, and i dont know how to find out. I do have a cable under the wall switch that goes to the cylinder. Not sure if this is proof. I also turned that switch on, probably a bad idea. I would guess that it just acts as an extra electric heater.

As far as the leaking valve is concerned, I think the culprit is the small red one next to the tundish (http://s1373.photobucket.com/user/MSachp/media/Mobile Uploads/IMG_20140303_195603_zpsigiykswc.jpg.html). If i turn it, the flow increases dramatically but turning it the other way does not fully stop it.

The red needle is indeed around 1bar but I thought that was for the heating system and not the hot water. Is there some way I can reduce the pressure? there must be a relieve valve somewhere.

Thanks. Much appreciate your help.

matelodave

As has been said, if the pressure relief valve is letting water flow into the tundish then it's either doing its job to release any over pressure in the system or it's faulty. The grey unit above is a 3bar pressure reducing valve and your relief valve (red knob) is set to go off at 6 bar (that's what is written on them) so one or the other isn't working properly and need to be either checked or replaced.

Twisting the relief valve will open it to clear any debris but it should then shut off fully if it is working properly unless the pressure has risen to above 6bar your mains water pressure has risen above 6bar which points to a faulty reducing valve.

Regarding your lack of hot water - see if you've got an immersion heater (trace the wiring back) or ensure that the fuse hasn't blown.
Hot water from the boiler should come via the motorised valve (white square box on the plumbing) - have a look to see if it's got a manual control - some have a small lever which can open & close the valve. They sometimes stick. Is your heating working ok. Does the pump run when the system calls for hot water or central heating. Check your programmer and tank thermostat are working.