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.
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...
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.
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...
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 !
According to Anglian Water the water in my area is Vert Hard.
I have had a bit of success using an un conventional method based around everyones advice that the TMV may be scaled.
Whilst the bath was running I tapped the TMV with a small hammer, as I was doing this all of a sudden the hot in...
No, it means that the problem is within the controls of the DHW operations.
Does the burner start up when HW is demanded? Possible flow switch problem.
Burner starts up ok every time. Flow switch was replaced last year due to intermittant hot water. This gave hot then stone cold water and I...
I can confirm that The flow pipe to the TMV also cools down when the hot water cools down, normally it is too hot to touch.
Does this mean the TMV is buggered?
Thanks for the reply.
AAV on heat store has been replaced and the cap is open but I never hear air coming out even when I drain the system and re fill? does the water in the store drain when the system is drained and re fill when I fill the system back up?
All manual air vents have been bled...
I have a problem with my Grant Vortex condensing combi 26 Oil boiler.
When I run the hot water for a bath after a few minutes the water runs luke warm, turn off the hot tap and wait a few minutes and it is hot again.
It always used to work ok.
The other thing I have noticed is I can hear air...