Grant Vortex Condensing Combi 26 hot water problems
- Thread starter didspip
- Start date
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Inhibitor will only protect the primary water. The TMV handles secondary water. For protection here you need a scale inhibitor, which many feel does nothing, but not fitting one invalidates any guarantee on affected parts. An electrolytic one fitted to the incoming mains should help, or an electronic/electrolytic one if feeling flush.
Just a thought, this boiler has a Ch pump and a DHW pump. Have you checked the operation of the DHW pump? Failure here gives exactly the problem you have.
Just a thought, this boiler has a Ch pump and a DHW pump. Have you checked the operation of the DHW pump? Failure here gives exactly the problem you have.
Thanks for the info. Can you suggest a scale inhibitor and how do I test the pump please?
All the merchants market their own, if I suggest, it will be moderated out probably, ask at your local counter, or Salamander or Liff is a start.
To check the pump, usually you can feel it working, but if you run the HW till it starts to go cold, check the flow temp of the pump outlet and see if that has gone cool. You can also turn the speed up and down and note the change in note.
To check the pump, usually you can feel it working, but if you run the HW till it starts to go cold, check the flow temp of the pump outlet and see if that has gone cool. You can also turn the speed up and down and note the change in note.
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Thank's again Oilhead, The pump is ok. I am going to attack the boiler this weekend and replace the TMV and Auto Air Vents and check the Heat Exchanger for Scale. I have also ordered a Scalemaster Gold inhibitor to fit to the cold supply. I will let you know how I get on. Wish me luck !
OK, After a lot of messing and some leaking drain taps I eventually replaced the TMV and the Non Return valves.
I checked the vessel and it was 1 bar with the system empty.
I pressurised the system to 1 bar cold and fired her up.
There is no bubbling noise any more and the bath filled without going cold.
On the cold inlet of the TMV there is a mesh that was half limed up.
The only thing that bothers me now is that it runs at 1.5 to 1.75 bar pressure.
Is this a normal running pressure or have I put too much water into the system?
I checked the vessel and it was 1 bar with the system empty.
I pressurised the system to 1 bar cold and fired her up.
There is no bubbling noise any more and the bath filled without going cold.
On the cold inlet of the TMV there is a mesh that was half limed up.
The only thing that bothers me now is that it runs at 1.5 to 1.75 bar pressure.
Is this a normal running pressure or have I put too much water into the system?
Shouldn't be a problem at under 2 bar. The limed up filter on the cold inlet gives you confirmation of the problem, when you bear in mind that the other cold inlet is to the heat exchanger. That may be scaled to some extent but time will tell.
I know a lot of people say the inhibitors are useless, but you should find that you will see less calcification round the hot taps than the cold.
I know a lot of people say the inhibitors are useless, but you should find that you will see less calcification round the hot taps than the cold.
Thanks to everyone on DIYnot for their help, especially Oilhead. I did look at the exchanger whilst I had the system drained and it seemed ok.
I will keep an eye on it.
Thanks' again,
TTFN.
I will keep an eye on it.
Thanks' again,
TTFN.
Hi didspip,
Thread revival!
I am having very similar sounding problems with our Grant 26e.
Our boiler is located in our kitchen and the hot water for the kitchen sink is always HOT. However, the taps/shower upstairs always start off hot (but not like in the kitchen) and then gradually becomes cooler and cooler.
Did you have anything like this before you replaced the TMV or where ALL your taps the same?
I don't feel confident replacing it myself, but may order one in for the engineer to fit next time he visits.
Thanks.
Thread revival!
I am having very similar sounding problems with our Grant 26e.
Our boiler is located in our kitchen and the hot water for the kitchen sink is always HOT. However, the taps/shower upstairs always start off hot (but not like in the kitchen) and then gradually becomes cooler and cooler.
Did you have anything like this before you replaced the TMV or where ALL your taps the same?
I don't feel confident replacing it myself, but may order one in for the engineer to fit next time he visits.
Thanks.
could be cold water passing through a mixer tap/shower upstairs
Hi,
The only other thing that caused a similar problem was having the water pressure too high. Has it been altered for any reason?
Lime scale clogging the TMV was my cause not letting enough through the valve, when I took it off it was rammed with scale.
Try adjusting it first then you will know if the valve is at fault. Mark it first before you adjust it. A small movement has a big effect.
The only other thing that caused a similar problem was having the water pressure too high. Has it been altered for any reason?
Lime scale clogging the TMV was my cause not letting enough through the valve, when I took it off it was rammed with scale.
Try adjusting it first then you will know if the valve is at fault. Mark it first before you adjust it. A small movement has a big effect.
I have adjusted the TMV and it appears to operate as expected.
Reading various threads suggest that it could be the diverter valve. Does a Grant Vortex 26E have one? I've had all the panels off but dont seem to be able to find it!? Are they buried in the inner workings? Is checking / replacing the diaphragm a DIY job?
Reading various threads suggest that it could be the diverter valve. Does a Grant Vortex 26E have one? I've had all the panels off but dont seem to be able to find it!? Are they buried in the inner workings? Is checking / replacing the diaphragm a DIY job?
No diverter valve on my Grant Vortex. Two pumps, one for water and one for heating. Not sure if the small wall mounted model is the same.
I still say your problem is lime somewhere. My heat exchanger has small filters on the inlets that were also limed up and reducing the water flow.
I still say your problem is lime somewhere. My heat exchanger has small filters on the inlets that were also limed up and reducing the water flow.
Thread revival, again!
My 26e is doing the same, the shower gradually will run cold after starting off hot.
I have found that if I manually turn off the central heating on the boiler control panel I will get constant hot water delivered to the shower, i.e. it is a temporary fix but I don't know why.
PCB and flow switch were replaced when the flow switch leaked and I don't remember having this problem before then.
The heat plate exchanger leaks and leaves a limescale deposit on the pipework below from the drip.
didspip and vanillaice, did you manage to resolve your issues?
Don't know whether this fault is pcb related or not. Any advice appreciated.
My 26e is doing the same, the shower gradually will run cold after starting off hot.
I have found that if I manually turn off the central heating on the boiler control panel I will get constant hot water delivered to the shower, i.e. it is a temporary fix but I don't know why.
PCB and flow switch were replaced when the flow switch leaked and I don't remember having this problem before then.
The heat plate exchanger leaks and leaves a limescale deposit on the pipework below from the drip.
didspip and vanillaice, did you manage to resolve your issues?
Don't know whether this fault is pcb related or not. Any advice appreciated.
1) Who says that oil is on the way out? Can you tell us when this is going to happen?
2) Why are you saying that prices are rising daily when domestic heating oil is the cheapest it has been for 3 odd years?
3) How much would it cost to install an "alternative heating source"
4) Oil boilers if looked after by a component boiler engineer can last years and in many cases way longer than a gas boiler will last. Some of the oil boilers on my books are in excess of 30 years old. How long does your average gas boiler last?
These sweeping statements are misleading.
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