Boiler not heating water.

irishguy

I have just moved into a house with a boiler that is about 9 years old (Potterton Ultra 260). It heats the rads fine, but it doesnt appear to heat the water at all. The pressure is zero bars, do you think this could cause the problem?

I had a look at the manual at it should be min .5 bar

Is it a big job to re pressurise the system and would it be a DIY job?

Also it appears that the previous occupants used the emersion for hot water

There doesnt appear to be any leaks in the system either

Pete67

Can you post up a picture of the cylinder and piping in your hot press and we'll go from there. It could be a simple matter of a closed valve.

irishguy

I am not a home for the next couple of days ill do it then. From memory there are 2 valves in the hot press. 1 on a plastic pipe coming out from the top of the cylinder (which is cold to the touch when the heating is on full).

The other valve is going into the cylinder from the side/middle an is on a copper pipe (red valve). This is warm at one side and cold at the other (the cylinder side) when the heating is on i tried opening and closing all valves, it didnt seem to have any affect. There is also a pump attached to that section of piping saying power extra (or something like that) with a slider set to auto (with a manual override setting) changing this appears to do nothing.

Anything else you need to know that might be useful?

items

irishguy wrote: »

I am not a home for the next couple of days ill do it then. From memory there are 2 valves in the hot press. 1 on a plastic pipe coming out from the top of the cylinder (which is cold to the touch when the heating is on full).

The other valve is going into the cylinder from the side/middle an is on a copper pipe (red valve). This is warm at one side and cold at the other (the cylinder side) when the heating is on i tried opening and closing all valves, it didnt seem to have any affect. There is also a pump attached to that section of piping saying power extra (or something like that) with a slider set to auto (with a manual override setting) changing this appears to do nothing.

Anything else you need to know that might be useful?

Could have some air built up in cylinder coil, if the heating has been left sitting for a while, air will go to the highest point. Normally the cylinder and top of some rads. At your cylinder you should have a bottle air vent, air vents tend to become blocked up with hard water, top of the bottle vent you should see a small cap that can be unscrewed, to bleed out any air trapped in cylinder coil pipework, try that first and bring a towel, it might not stop weeping, might need replacing.

Avns1s

Perhaps the hot water is on a separate zone from the heating and either the valve is stuck (possibly the motorised valve) or else the circulation pump isnt operating. You might need to remove the screw on cover in the middle of the pump and turn the shaft with a screwdriver to free it.

irishguy

items wrote: »

Could have some air built up in cylinder coil, if the heating has been left sitting for a while, air will go to the highest point. Normally the cylinder and top of some rads. At your cylinder you should have a bottle air vent, air vents tend to become blocked up with hard water, top of the bottle vent you should see a small cap that can be unscrewed, to bleed out any air trapped in cylinder coil pipework, try that first and bring a towel, it might not stop weeping, might need replacing.

I let the air out of the radiators, but there is another vent in the hot press that I must try also.

Perhaps the hot water is on a separate zone from the heating and either the valve is stuck (possibly the motorised valve) or else the circulation pump isnt operating. You might need to remove the screw on cover in the middle of the pump and turn the shaft with a screwdriver to free it.

The pump is built into the boiler (I think). So I may have to get someone out then...

items

irishguy wrote: »

I let the air out of the radiators, but there is another vent in the hot press that I must try also.




The pump is built into the boiler (I think). So I may have to get someone out then...

I'd say its just coil with air from faulty bottle vent. If you are brave enough you can crack open the nut below vent a little then move it around. If you hear a hiss of air keep it loose until you find water. Failing that you could crack open nut going into coil and repeat the above process, but word of caution, be careful with coil nut as it could twist at cylinder and damage coil.

Try it if you feel up to it, leave boiler running at lowest temp setting to help move water, bring a towel up to hot press and open either nut slightly to remove possible air, might save you a few bob. If you can remove the air issue you'll be charged less should it not be the problem. First thing a calling plumber should do is as I've just described.

Best of luck.

irishguy

Pete67 wrote: »

Can you post up a picture of the cylinder and piping in your hot press and we'll go from there. It could be a simple matter of a closed valve.

Here are some photos.


I opened the vent (in Pic 2) and some air came out I then left it on loose so air can escape. No water came out.



I tried loosening both nuts but they were quite tight and the pipe was just turning. So I stopped incase i damaged something. Any other ideas or is it time to call a plumber?


Photo 1
http://farm5.static.flickr.com/4030/4228679434_8478c74481_o.jpg

Photo 2
http://farm5.static.flickr.com/4033/4227912017_0c0ed9cd08_o.jpg

Photo 3
http://farm3.static.flickr.com/2486/4227912315_b24c6d2f56_o.jpg

Photo 4
http://farm3.static.flickr.com/2758/4228681344_4366a07f99_o.jpg

Photo 5
http://farm3.static.flickr.com/2615/4228680764_dc30910de2_o.jpg

Pete67

It's not completely clear from the pictures how the cylinder in plumbed into the boiler primaries, but the following may help. The balancing valve at the top of pic 4, is it open or closed? It should normally be open about 1/2 to 1 turn.

Working on the basis that the coil may be airlocked, can you open that valve fully, and then go around all the radiators and turn them off (or if the zone valve in pic 5 controls all the rads just make sure it stays closed - thermostat to minimum). Then start the boiler on a low temp setting and see if the coil gets warm. It should. Hopefully the pump will provide enough head to move the trapped air around to the vent so it gets removed.

If successful then you will need to close down the valve again or the radiators will be bypassed and not heat properly. Close it completely and then open 1/2 to 1 turn. Turn your radiators back on and ensure they all heat. You may need to tweak the balancing valve a little to get everything settled - open slightly to increase circulation to the cylinder if it takes too long to heat, and close it slightly if the radiators do not heat fully. I'm assuming the radiators are balanced properly already as you indicated that they are working fine. Best of luck.

stillbornalive

Hi Irishguy

when you bled the rad did you top up the pressure in the system?

In the fifth picture you have a motorized valve, dose the light come on when you turn on your heating/hotwater switch and dose it make any noise? this could be the sorce of your problems if it is in line with the pipe work leading in to the bottom of the cylinder. if you are unsure if it is working , turn off your heating, unscrew it from its bracket

Be care do not disconnect live wiring, Make sure that the power to it has been turned off if your unsure get a professional

now on the bracket/fitting you will see a raised piece of metal that will turn if you turn it manually a quarter turn is usually enough. turn on the heating as see if the water in the cylinder heats up. if so then you valve is gone an needs to be replaced

hope this is some help

edit also pete 67 could be right .. i didnt see the balancing valve oops

items

Just seen pictures, hard to make out heating pipe work. The half inch valve, with fitting (NRV) below valve is your heating filler valve, you should have that open during normal boiler use.

All other valves at that level should be plumbing valves, one to turn off hot, other to turn off cold. Good idea would be marking wall or bit of masking tape on pipe, to mark each valve.

You have a motorized valve, could either control heating for summer or flow of heat to cylinder. From pictures, I'd say its for heating, might have a switch somewhere to turn off rads during summer.

I cant see any cylinder stat so looks like you've no control over hot water, apart from boiler.

Coil pipes seem to be further apart than I am used to seeing, also top pipe, its got a valve on it, make sure thats only barely open. It should be on the bottom one, when all is well, make sure the bottom pipe heats up first, if not valve is on wrong pipe. Its piped upside down, but some do that, once valve is on return it will still work just as well.

From tracing pipes, looks like your bottle vent is connected to the return, but it might not be, just a case of cylinder coil piped upside down. Might not be the coil I see in pictures, but its the impression I get from picture only.

Over all, some confusion in hot press, different pipe material, fittings, valves facing different ways, untidy. Shower pump might be a bugger to replace. if its still under guarantee, you wont be covered, has to be 4 valves very close to pump for service person.

Sorry to be bearer of bad news, might never have any trouble, just untidy, and missing those pump isolation valves.

Try venting again, if valve for filling heating is / was closed, opening it will make big difference.