Grants Vortex eco 26-35 over pressurising

[Jezwillmar]

I have grants vortex oil fired boiler. Sealed system heating and separate water cylinder. I’ve gone to turn the heating on ironically to check all working before winter and it’s over pressurising up to 2.5 bar then operating the the prv.Before I turn it off.

Over time it then returns down to .5bar and holds.

Fill loop isolated in 2 places no water passing.

It is also over pressurising when heating the hot water up as well. Not just the heating circuit.

When boiler turned off a gurgling/chugging noise coming from inside the boiler.

I followed advice on here and checked/changed the vessel and feed pipe and the vessel did have water in. However the the problem still occurs.

Stuff done so far.
New vessel base pressure 1 bar
New vessel feed pipe lots of flow when draining the system via pipe and clear.
Cleaned the mag filter.
Flushed out the heating loop. And re pressurised to .5bar.

 

[oilhead]

Does the heating circulate when swithched on? Could be airlocked.

 

[Johntheo5]

I have grants vortex oil fired boiler. Sealed system heating and separate water cylinder. I’ve gone to turn the heating on ironically to check all working before winter and it’s over pressurising up to 2.5 bar then operating the the prv.Before I turn it off.

Over time it then returns down to .5bar and holds.

Fill loop isolated in 2 places no water passing.

It is also over pressurising when heating the hot water up as well. Not just the heating circuit.

When boiler turned off a gurgling/chugging noise coming from inside the boiler.

I followed advice on here and checked/changed the vessel and feed pipe and the vessel did have water in. However the the problem still occurs.

Stuff done so far.
New vessel base pressure 1 bar
New vessel feed pipe lots of flow when draining the system via pipe and clear.
Cleaned the mag filter.
Flushed out the heating loop. And re pressurised to .5bar.

If the new is EV precharged to 0.5bar and charged to 1.0bar (cold) then it shouldn't go lower than 1.0bar when system returns to cold.
What size is the EV.
Assuming a boiler flow temp of 70C and assuming precharge/filling pressures of 0.5bar/1.0bar with a maximum final (hot) pressure of 2.25bar...
a 6L EV will be OK for a 79L system, a 8L OK for 110L, a 10L OK for 132L and a 12L OK for 159L, so 8L or > should be OK for 8 to 10 rads.
Can you say clearly what the precharge (air end) pressure is and also the filling pressure, I've assumed 0.5bar/1.0bar.
You say there are two filling system isol valves but better to remove one end of the filling loop to rule out any leakage into the EV.

A cobi boiler could pressurize the system (via the mains) if the plate heat exchanger developed a leak but the pressure would not return to normal.

 

[Exedon]

Grant did have a batch of faulty plate to plate heat exchanges at one point.
We changed several under warranty.
As above physical disconnect filling loop as first check.
The combis can be quite difficult to clear of air. If yours has mostly manual air valves the one on return often needs clearing several times .

 

[Jezwillmar]

Hi thanks for the responses. It’s not a combi I don’t think it has a separate water cylinder.

Heat was getting upstairs to the furthest radiator and creeps up slowly to above 1.5 bar after I’ve re bled everything again.

The EV is a like for like internal 12 L as per Grants website.

On the hot water loop it shot ip and was air steam bled from the mag filter so maybe a separate issue of the auto bleed valve not working? Looks a bit rough so I’ll replace that tomorrow

 

[Exedon]

Be extremely careful changing that auto air valve.
Spanner on socket it goes into first that copper pipe its attached to distorts/leaks for fun.

 

[Jezwillmar]

Ok thought I’d update. The system is now all fixed. Running better than it ever had. I replaced the auto bleed valve. I checked the pump was free to rotate and was all good.

After all the parts I replaced I put a system cleaner through the heating and flushed out a lot of debris. Cleaned off the mag filter and added the additive.

There was a lot of air bled out as expected and all good.

Thanks for all the help.

 

[Jezwillmar]

Ok thought I’d update. The system is now all fixed. Running better than it ever had. I replaced the auto bleed valve. I checked the pump was free to rotate and was all good.

After all the parts I replaced I put a system cleaner through the heating and flushed out a lot of debris. Cleaned off the mag filter and added the additive.

There was a lot of air bled out as expected and all good.

Thanks for all the help.

Also to note the previous “professional” heating engineer left the boiler with missing screws and the two temp probes not in the side holder of the boiler so I suspect it was overheating the water as well. They’re all back in the proper location.