Grant boiler doesnt like nights

[topdrive]

Got a grant vortex 26e

Couple years old

had a new expansion vessel and prv fitted not so long ago - was dropping pressure over a couple of weeks before this.

Now its started gurgling the radiators upstairs at 4am when the heatings due to come on and dumping pressure somewhere. Yet it will stay on all day without issue once its been pressured , It even holds pressure cold all day. Just at 4 am it likes to dump.

Before i get the plumber back i decided to look all over the pipes , rads and trvs but see nothing.

Am i looking at a big bill again ?

 

[stardanny]

Does the water come out of PRV at 4am?

Fill up to normal pressure, disconnect filling loop and see what happen at 4am.

If it is losing water, and not coming from PRV, you have a leak somewhere, maybe from air vent, but 4am, strange.

Daniel.

 

[oilhead]

Check round the auto air vents for leakage. Also, when the boiler is hot, is there water in the expansion vessel? It wouldn't be the first Grant where the flexi from the boiler is blocked, which means when the boiler runs in the day it will dump your pressure, and cool down over night so registering nil pressure, hence gurgling.

 

[topdrive]

Sorted.

Suspected the pressure gauge was shot , i was right , stuck my pump on the expansion vessel

Pressured the system back up.

1 bar in the vessel . Put pressure in the system , up to 2 bar . Gauge reads zero. Put gauge to 1 bar and it reads 2 , so the boiler trips the prv when it came on

Had a new gauge fitted and it worked a dream last night for the first time in 3 weeks

 

[holty]

well done. and i say that without taking the **** ... reason being the pressure gauge can throw even the experienced. had a call from one of the work lads saying when he turned on a hot tap the pressure would drop. reason he was there was to check out a so called boiler pressure drop . thought he must be off his nuts. so i goes round and he was right. after some fecking about. turns out when the dhw pump was on (negative pressure), it would eventually pull the gauge needle to its rightfull position. needless to say, a partially cruded up low water pressure switch didnt help either.

 

[topdrive]

it was a relief this morning to get up and find - 1 bar in the system.

need to get it dosed up tonight - some fernox cleaner to go in for now.

can any one suggest a good all in one inhibitor/antifreeze for the system - its an external combi.

we get extended power cuts during winter and i can drain the hot water easy but draining the heating is expensive putting inhibitor back in every time and a hassle - cant expect my mrs to go under the floor and drop the heating water every power cut.

 

[holty]

fernox alphi 11. use it alot on static homes etc

 

[topdrive]

cheers , will get me some of that next week before i drop the cleaner out